Enable Windows support for BuildKit integration tests

[rzlink]

This PR adds comprehensive Windows container support to BuildKit's integration test suite, enabling cross-platform testing while maintaining full Linux compatibility.

Changes

• Updated 35+ integration tests to work on both Windows and Linux
• Uses integration.UnixOrWindows() pattern for platform-specific logic
• Windows: nanoserver images, cmd.exe commands, C:\ paths, CRLF handling
• Linux: preserves existing alpine/busybox images and bash/sh commands
• Added platform-specific adaptations for cache, export, frontend, and CLI tests

Tests requiring POSIX features (uid/gid, tmpfs, file modes) remain Linux-only.

[rzlink]

Summary

• Total Tests: 115 (currently skipped) + 14 (CI-failing) + 32 (fixed) = 161 total
• Linux-Only Concept: 76
• Command Complexity: 35
• Conversion Issues: 2
• Flaky on Windows: 2
• Other Reasons: 0
• Tests Fixed: 32 (12 unnecessary skips, 20 source code fixes)
• CI-Failing Tests: 14 (work locally but fail in GitHub Actions)

---

Test Status Table

Test Name	File Path	Skip Reason	Detailed Reason	Test Category	BuildKit Feature	Windows Feasible	Priority	Effort Estimate
testCDI	client/client_cdi_test.go	Linux-Only Concept	CDI (Container Device Interface) uses Linux-specific device access patterns (/dev/ files, Unix permissions). Windows containers use different isolation models and device driver interfaces.	Container Runtime	CDI Device Interface	No	Not Planned	Very High
testCDINotAllowed	client/client_cdi_test.go	Linux-Only Concept	CDI specification designed for Linux OCI runtimes. Windows container device access fundamentally different (Windows Driver Model vs Unix device nodes).	Container Runtime	CDI Device Interface	No	Not Planned	Very High
testCDIEntitlement	client/client_cdi_test.go	Linux-Only Concept	Tests device entitlements using Linux container runtime assumptions. Windows containers require different privilege/entitlement models for device access.	Security/Permissions	CDI Device Interface	No	Not Planned	Very High
testCDIFirst	client/client_cdi_test.go	Linux-Only Concept	CDI device injection assumes Linux-style device mounting and busybox container environment. Windows lacks equivalent CDI implementation.	Container Runtime	CDI Device Interface	No	Not Planned	Very High
testCDIWildcard	client/client_cdi_test.go	Linux-Only Concept	Tests CDI wildcard device matching using Linux device enumeration patterns. Windows device discovery and matching works differently.	Container Runtime	CDI Device Interface	No	Not Planned	Very High
testCDIClass	client/client_cdi_test.go	Linux-Only Concept	Tests CDI device class handling specific to Linux container runtimes. Windows would need separate CDI implementation for device classification.	Container Runtime	CDI Device Interface	No	Not Planned	Very High
testAddGitSHA1	frontend/dockerfile/dockerfile_addgit_test.go	Command Complexity	Uses Alpine base image with apk add git and Linux shell commands. Requires Windows base images, Git for Windows installation, and PowerShell/cmd syntax conversion.	Build Process	Dockerfile ADD Git	Yes	Medium	High
testAddGitSHA256	frontend/dockerfile/dockerfile_addgit_test.go	Command Complexity	Git checksum validation using Linux commands and Alpine package manager. Needs Windows container with Git, PowerShell commands, and Windows file permission handling.	Build Process	Dockerfile ADD Git	Yes	Medium	High
testAddGitChecksumCache	frontend/dockerfile/dockerfile_addgit_test.go	Command Complexity	Git repository caching with Linux-style paths and bash commands. Requires Windows Git installation, PowerShell syntax, and Windows path handling adaptations.	Build Process	Dockerfile ADD Git	Yes	Medium	High
testGitQueryString	frontend/dockerfile/dockerfile_addgit_test.go	Command Complexity	Git URL query string handling using Alpine + bash. Needs Windows base image, Git for Windows, and PowerShell command conversion for git operations.	Build Process	Dockerfile ADD Git	Yes	Medium	High
testRunGlobalNetwork	frontend/dockerfile/dockerfile_runnetwork_test.go	Linux-Only Concept	Tests network isolation using busybox + netcat (nc) commands. Windows containers have different networking architecture and lack netcat. Network entitlements work differently on Windows.	Network/Registry	RUN Network Modes	No	Low	Very High
testSecretFileParams	frontend/dockerfile/dockerfile_secrets_test.go	Command Complexity	Tests secret mounting with busybox + Unix file permission commands (stat -c, uid/gid/mode). Windows containers don't have stat command or Unix-style file permissions.	Security/Permissions	Secret Mounts	Yes	High	High
testSecretRequiredWithoutValue	frontend/dockerfile/dockerfile_secrets_test.go	Command Complexity	Basic secret mount error testing with busybox. Simpler than other secret tests but still uses Linux container and shell syntax.	Security/Permissions	Secret Mounts	Yes	High	Medium
testSecretAsEnviron	frontend/dockerfile/dockerfile_secrets_test.go	Command Complexity	Tests secret as environment variable with busybox + bash test syntax. Uses /run/secrets path and Linux shell operators that need PowerShell conversion.	Security/Permissions	Secret Mounts	Yes	High	High
testSecretAsEnvironWithFileMount	frontend/dockerfile/dockerfile_secrets_test.go	Command Complexity	Tests combined secret file + environment mounting with busybox + bash. Uses /run/secrets paths and Linux test operators requiring Windows command conversion.	Security/Permissions	Secret Mounts	Yes	High	High
testChmodNonOctal	frontend/dockerfile/dockerfile_chmod_non_octal_test.go	Linux-Only Concept	Tests COPY --chmod with symbolic permission modes (e.g., u+rwx, g-w) which are POSIX-specific. Windows has fundamentally different permission model and doesn't support symbolic chmod modes.	File System	COPY --chmod	No	Not Planned	Very High
testMountTmpfs	frontend/dockerfile/dockerfile_mount_test.go	Linux-Only Concept	Tests tmpfs (temporary filesystem) mounting which is a Linux kernel feature for RAM-based filesystems. Windows has no equivalent tmpfs concept or implementation.	File System	RUN Mount tmpfs	No	Not Planned	Very High
testMountTmpfsSize	frontend/dockerfile/dockerfile_mount_test.go	Linux-Only Concept	Tests tmpfs size limits, another Linux kernel-specific feature. Windows containers use different memory management and have no tmpfs equivalent for temporary RAM filesystems.	File System	RUN Mount tmpfs	No	Not Planned	Very High
testCacheMountUser	frontend/dockerfile/dockerfile_mount_test.go	Linux-Only Concept	Tests cache mount with POSIX-specific uid=1001, gid=1002, mode=0751 permissions. Windows containers don't have Unix user/group ID concepts or POSIX file permission modes.	Cache Management	RUN Mount Cache	No	Not Planned	Very High
testCacheMountParallel	frontend/dockerfile/dockerfile_mount_test.go	Flaky on Windows	Cache mount parallel execution test that works but produces unreliable results on Windows Server 2025. Needs investigation for Windows-specific timing or concurrency issues.	Cache Management	RUN Mount Cache	Yes	Low	Medium
testSSHSocketParams	frontend/dockerfile/dockerfile_ssh_test.go	Linux-Only Concept	Tests SSH socket mounting with Unix socket file descriptors. Windows containers don't support Unix domain sockets and use different SSH agent communication methods (named pipes).	Security/Permissions	RUN Mount SSH	No	Not Planned	Very High
testSSHFileDescriptorsClosed	frontend/dockerfile/dockerfile_ssh_test.go	Linux-Only Concept	Tests SSH file descriptor cleanup using Unix socket mechanisms. Windows SSH agent communication doesn't use Unix file descriptors and has different cleanup requirements.	Security/Permissions	RUN Mount SSH	No	Not Planned	Very High
testOutlineSecrets	frontend/dockerfile/dockerfile_outline_test.go	Command Complexity	Tests frontend outline parsing of secret/SSH mount syntax using busybox/alpine base images and bash commands. Frontend parsing should work on Windows but test uses Linux containers and syntax.	Frontend/Dockerfile	Frontend Outline	Yes	Medium	Medium
testExcludedFilesOnCopy	frontend/dockerfile/exclude_patterns_test.go	Command Complexity	Tests COPY/ADD --exclude functionality with file pattern exclusions and Git repository setup. Uses complex file operations and git commands that may behave differently on Windows paths and filesystem.	Build Process	COPY/ADD --exclude	Yes	High	High
testGitProvenanceAttestation	frontend/dockerfile/dockerfile_provenance_test.go	Linux-Only Concept	Tests SLSA provenance with Git working directory bind-mounts. Windows containerd lacks bind-mount support for Git operations, causing path/configuration errors in containers.	Security/Permissions	SLSA Provenance	No	Not Planned	Very High
testMultiPlatformProvenance	frontend/dockerfile/dockerfile_provenance_test.go	Linux-Only Concept	Tests provenance for multi-architecture builds (linux/amd64, linux/arm64) using busybox. Hardcoded to expect Linux platforms only, no Windows platform support.	Build Process	SLSA Provenance	No	Low	Very High
testClientFrontendProvenance	frontend/dockerfile/dockerfile_provenance_test.go	Linux-Only Concept	Tests provenance with client frontend using busybox and alpine. Hardcoded to expect Linux platforms and uses Linux-specific container assumptions.	Frontend/Dockerfile	SLSA Provenance	No	Low	Very High
testSecretSSHProvenance	frontend/dockerfile/dockerfile_provenance_test.go	Linux-Only Concept	Tests provenance for secret and SSH mounts using busybox. Validates SSH mount functionality which is Linux-specific (Unix sockets) and incompatible with Windows.	Security/Permissions	SLSA Provenance	No	Not Planned	Very High
testOCILayoutProvenance	frontend/dockerfile/dockerfile_provenance_test.go	Command Complexity	Tests SLSA provenance with OCI layout export using scratch base image and registry push operations. OCI layout export is supported on Windows but test uses scratch base image which is Linux-specific. Requires adaptation to use Windows base images and Windows-compatible provenance validation.	Build Process	SLSA Provenance	Yes	Medium	High
testCommandSourceMapping	frontend/dockerfile/dockerfile_provenance_test.go	Command Complexity	Tests provenance command source mapping using alpine base image. Core provenance functionality should work on Windows but requires Windows container adaptation.	Build Process	SLSA Provenance	Yes	Medium	High
testDuplicateLayersProvenance	frontend/dockerfile/dockerfile_provenance_test.go	Command Complexity	Tests provenance for duplicate layer detection using busybox. Provenance layer tracking should work on Windows with container adaptation.	Build Process	SLSA Provenance	Yes	Medium	High
testProvenanceExportLocal	frontend/dockerfile/dockerfile_provenance_test.go	Command Complexity	Tests local provenance export using busybox and scratch. Core export functionality should work on Windows with container/command adaptations.	Build Process	SLSA Provenance	Yes	Medium	High
testProvenanceExportLocalForceSplit	frontend/dockerfile/dockerfile_provenance_test.go	Command Complexity	Tests forced split provenance export using busybox and scratch. Export splitting logic should work on Windows with container adaptations.	Build Process	SLSA Provenance	Yes	Medium	High
testProvenanceExportLocalMultiPlatform	frontend/dockerfile/dockerfile_provenance_test.go	Linux-Only Concept	Tests multi-platform local provenance export with hardcoded Linux platform expectations. Platform-specific logic prevents Windows compatibility.	Build Process	SLSA Provenance	No	Low	Very High
testProvenanceExportLocalMultiPlatformNoSplit	frontend/dockerfile/dockerfile_provenance_test.go	Linux-Only Concept	Tests multi-platform provenance without splitting, hardcoded for Linux platforms. Platform validation logic incompatible with Windows.	Build Process	SLSA Provenance	No	Low	Very High
testDefaultEnvWithArgs	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests Unix shell parameter expansion in ENV statements (${var#prefix}, ${var:-default}, ${var%%suffix}). Windows cmd.exe and PowerShell don't support these Unix-specific expansions.	Frontend/Dockerfile	ENV Variable Expansion	No	Not Planned	Very High
testCopyLinkDotDestDir	frontend/dockerfile/dockerfile_test.go	Command Complexity	Tests COPY --link functionality with dot destination directories using diffApply for file validation. diffApply utility requires complex Unix file system comparisons that would need Windows-specific adaptation.	Build Process	COPY --link	Yes	Medium	High
testCopyLinkEmptyDestDir	frontend/dockerfile/dockerfile_test.go	Command Complexity	Tests COPY --link with empty destination directories using diffApply for directory structure validation. Complex file system validation logic needs Windows-compatible implementation.	Build Process	COPY --link	Yes	Medium	High
testTarExporterMulti	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests multi-platform TAR export with hardcoded verification for Linux/Darwin platforms (linux/amd64,darwin/amd64). Platform-specific paths like "linux_amd64/forlinux" are hardcoded, excluding Windows platform support.	Build Process	TAR Export Multi-Platform	No	Low	Very High
testWorkdirSourceDateEpochReproducible	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests reproducible builds with SOURCE_DATE_EPOCH using alpine base image and OCI exporter features. Relies on Linux-specific SOURCE_DATE_EPOCH behavior and OCI export functionality not fully supported on Windows.	Build Process	Reproducible Builds	No	Not Planned	Very High
testCopyChownExistingDir	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests COPY --chown functionality with complex POSIX ownership validation using busybox, chown commands, and stat -c "%u:%g" for uid:gid verification. Windows containers don't support Unix user/group ownership concepts.	File System	COPY --chown	No	Not Planned	Very High
testWorkdirCopyIgnoreRelative	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests WORKDIR with COPY --from using scratch base image and relative path handling. Uses scratch base image which is fundamentally Linux-specific - Windows containers require a base layer with Windows runtime components.	Build Process	Multi-stage Builds	No	Not Planned	Very High
testCopyChownCreateDest	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests COPY --chown with user/group creation using busybox, adduser commands, and stat -c "%U %G" for ownership verification. Windows containers use different user management and don't support Unix-style user/group ownership.	File System	COPY --chown	No	Not Planned	Very High
testCopySocket	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests COPY of Unix domain sockets using fstest.CreateSocket() and socket file handling. Windows doesn't support Unix domain sockets in the same way - uses named pipes instead for IPC.	File System	COPY Operations	No	Not Planned	Very High
testDefaultShellAndPath	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests multi-platform builds with hardcoded validation for Linux/Windows shell defaults (/bin/sh vs cmd). While test mentions Windows, it uses scratch base and validates platform-specific defaults that need separate Windows test logic.	Build Process	Multi-Platform Builds	No	Low	Very High
testExportMultiPlatform	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests multi-platform export with platform-specific file creation (windows/amd64,linux/arm,linux/s390x) but uses scratch base and hardcoded platform combinations. Relies on Linux context and validation logic.	Build Process	Multi-Platform Builds	No	Low	Very High
testPullScratch	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests pulling and building from scratch base image with registry operations. Scratch is Linux-specific base - Windows containers require actual base layer with Windows runtime components and registry functionality.	Build Process	Registry Operations	No	Not Planned	Very High
testDockerfileADDFromURL	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ADD instruction with HTTP URL downloads using scratch base image and file validation. Scratch base is Linux-specific and file handling needs Windows container adaptation.	Build Process	ADD HTTP URLs	No	Low	Very High
testDockerfileAddChownArchive	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ADD --chown with TAR archive extraction using scratch base and TAR header uid/gid validation. Windows containers don't support Unix ownership concepts and scratch base is Linux-specific.	File System	ADD --chown	No	Not Planned	Very High
testDockerfileAddChownExpand	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ADD --chown with variable expansion using busybox, stat -c "%u %G" commands for ownership verification. Windows containers don't support Unix user/group concepts or stat command syntax.	File System	ADD --chown	No	Not Planned	Very High
testSymlinkDestination	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ADD/COPY to symlink destinations using scratch base and TAR symlink creation. Windows has different symlink support and scratch base is Linux-specific.	File System	Symlink Handling	No	Not Planned	Very High
testDockerfileCopyFromArgs	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests COPY --from with variable expansion error handling using scratch base. While test validates error cases, scratch base is fundamentally Linux-specific.	Build Process	COPY --from	No	Low	Very High
testDockerfileScratchConfig	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests scratch image configuration and environment variables using containerd worker. Scratch image concept is Linux-specific - Windows containers need actual base layers.	Build Process	Image Configuration	No	Not Planned	Very High
testExportedHistory	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests exported image history with multi-stage builds using busybox and containerd worker validation. Uses Linux container assumptions and containerd-specific image inspection.	Build Process	Image History	No	Low	Very High
testUser	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests comprehensive USER directive functionality with extensive Unix user/group validation using busybox and commands like id -u, id -g, id -un, id -gn, id -G, id -Gn. Windows containers use fundamentally different user identity models (SIDs vs UIDs).	Security/Permissions	USER Directive	No	Not Planned	Very High
testUserAdditionalGids	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests USER directive additional group IDs (CVE-2023-25173) using busybox and Unix id command validation. Windows doesn't have Unix group ID concepts - uses different group membership models.	Security/Permissions	USER Directive	No	Not Planned	Very High
testCopyChown	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests COPY --chown with user/group ownership using busybox and stat -c "%U %G" for ownership validation. Despite comment suggesting Windows compatibility, requires fundamental rewrite from UIDs to SIDs - not simple adaptation.	File System	COPY --chown	No	Not Planned	Very High
testCopyChmod	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests COPY --chmod with Unix file permissions using busybox and stat -c "%04a" for octal permission validation. Windows file permissions work differently (ACLs vs Unix modes) and don't use octal notation.	File System	COPY --chmod	No	Not Planned	Very High
testCopyInvalidChmod	frontend/dockerfile/dockerfile_test.go	Command Complexity	Tests COPY --chmod error handling with invalid permission syntax. Core error validation logic should work on Windows but needs adaptation for Windows permission validation instead of Unix octal modes.	File System	COPY --chmod	Yes	Medium	High
testAddURLChmod	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ADD --chmod with HTTP URL downloads using busybox and stat -c "%%04a" for permission validation. Combines Unix permission concepts with URL downloading that needs Windows permission adaptation.	Build Process	ADD --chmod	No	Low	Very High
testDockerfileFromGit	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests Dockerfile builds from Git repositories using HTTP server and Git context functionality. BuildKit's git utility (util/gitutil/git_cli.go) hardcodes HOME=/dev/null to disable user gitconfig, but /dev/null is Unix-specific and doesn't exist on Windows. This is a fundamental architectural issue requiring git utility rewrite for Windows compatibility.	Build Process	Git Context Integration	No	Not Planned	Very High
testOnBuildWithChildStage	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ONBUILD functionality with multi-stage builds and registry operations using busybox base image and extensive Unix shell commands. Uses bash test operators [ -f ], [ ! -f ], Unix commands (mkdir -p, echo -n, touch, rm), and scratch base image. ONBUILD feature itself could work on Windows but test implementation is deeply Unix-dependent.	Build Process	ONBUILD Multi-Stage	No	Low	Very High
testOnBuildNewDeps	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ONBUILD with cross-stage dependencies using busybox and alpine base images, Unix commands (cat for file processing), and scratch base image. ONBUILD copies /etc/alpine-release from alpine image, processes it with cat command, requires Linux containers and Unix file system paths.	Build Process	ONBUILD Dependencies	No	Low	Very High
testCacheMultiPlatformImportExport	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests cache import/export across multiple platforms using busybox base image and Unix commands (/dev/urandom, head -c, sha256sum). Hardcoded for linux/amd64,linux/arm/v7 platforms with Linux-specific random data generation and scratch base image. Platform validation assumes Linux-only environments.	Cache Management	Cache Multi-Platform	No	Low	Very High
testCacheMountModeNoCache	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests cache mount with no-cache mode using busybox base image and Unix commands (touch, ls -l, wc -l) with Unix file permission mode 0773. Validates cache behavior by counting directory entries and relies on Unix-specific file listing and permission concepts.	Cache Management	Cache Mount No-Cache	No	Low	Very High
testPlatformArgsExplicit	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests platform argument handling with explicit platform targeting using busybox base image and Unix commands (mkdir, echo -n). Hardcoded to darwin/ppc64le platform validation and scratch base image. Platform testing logic assumes non-Windows environments and Linux container execution.	Build Process	Platform Arguments	No	Low	Very High
testShmSize	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests shared memory size configuration using busybox base image and Linux-specific /dev/shm filesystem mount inspection. Uses mount command to grep /dev/shm and validate shm-size parameter. Windows containers don't have /dev/shm or equivalent shared memory filesystem concept.	Container Runtime	Shared Memory	No	Not Planned	Very High
testUlimit	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests ulimit (user limits) configuration using busybox base image and Unix ulimit command to query file descriptor limits. Windows doesn't have ulimit concept - uses different resource limit management through Windows APIs and job objects.	Container Runtime	User Limits	No	Not Planned	Very High
testCgroupParent	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests cgroup parent assignment using alpine base image and Linux cgroup v2 filesystem (/sys/fs/cgroup). Creates cgroup hierarchy, sets pids.max limit, and validates container execution within cgroup constraints. Windows containers use job objects, not cgroups.	Container Runtime	Cgroup Management	No	Not Planned	Very High
testNamedImageContext	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests named image context functionality using busybox and alpine base images with Unix commands (cat /etc/alpine-release, env grep). Uses scratch base image and bash test operators [ -f ], [ ! -f ]. Complex registry operations with Linux-specific file paths and environment variable processing.	Build Process	Named Image Context	No	Low	Very High
testNamedMultiplatformInputContext	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests named context with multi-platform input using alpine base image and hardcoded linux/amd64,linux/arm64 platforms. Uses scratch base image and TARGETARCH build arguments specific to Linux architectures. Platform resolution logic assumes Linux-only environments.	Build Process	Named Multi-Platform Context	No	Low	Very High
testNamedFilteredContext	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests named context with filtering capabilities using alpine and scratch base images. Complex file transfer validation with regex patterns and mount operations. Uses Linux-specific file system operations and scratch base which is Linux-only.	Build Process	Named Filtered Context	No	Low	Very High
testSourceDateEpochWithoutExporter	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests SOURCE_DATE_EPOCH functionality using scratch base image which is Linux-specific. While OCI exporter is supported on Windows, scratch base images are fundamentally incompatible with Windows containers which require actual base layers with Windows runtime components.	Build Process	SOURCE_DATE_EPOCH	No	Not Planned	Very High
testSBOMScannerImage	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests SBOM (Software Bill of Materials) scanning using busybox base image and Unix shell script with heredoc syntax. Uses scratch base image and complex bash scripting for SBOM generation. SBOM attestation features may have platform-specific behavior differences on Windows.	Security/Permissions	SBOM Scanning	No	Low	Very High
testSBOMScannerArgs	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests SBOM scanner with build arguments using busybox and scratch base images. Uses Unix shell commands and heredoc syntax for SBOM generation. SBOM attestation functionality and scanner execution model assumes Linux container environment.	Security/Permissions	SBOM Scanning	No	Low	Very High
testOCILayoutMultiname	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests OCI layout export with multiple names using scratch base image. While Windows BuildKit does support OCI exporters, scratch base images are fundamentally Linux-specific and incompatible with Windows containers which require actual base layers with Windows runtime components.	Build Process	OCI Layout Export	No	Not Planned	Very High
testReproSourceDateEpoch	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests reproducible builds with SOURCE_DATE_EPOCH using busybox base image and OCI exporter. Explicitly targets Linux platform and uses OCI format handling. SOURCE_DATE_EPOCH behavior and OCI export functionality not fully supported on Windows containers.	Build Process	Reproducible Builds	No	Not Planned	Very High
testMultiNilRefsOCIExporter	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests multi-platform OCI export with nil references using scratch base image targeting linux/amd64,linux/arm64,linux/s390x platforms. Requires OCI exporter not supported on Windows BuildKit and uses scratch base incompatible with Windows containers.	Build Process	OCI Multi-Platform Export	No	Not Planned	Very High
testEagerNamedContextLookup	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests eager named context lookup using alpine base image and extensive bash commands with complex shell scripting. Uses Unix-specific commands, file operations, and shell syntax incompatible with Windows container environments.	Build Process	Eager Context Lookup	No	Low	Very High
testPlatformWithOSVersion	frontend/dockerfile/dockerfile_test.go	Linux-Only Concept	Tests platform-specific OS version validation using scratch base image. Explicitly skipped on Windows: "FROM scratch and layer formatting not being supported on Windows." Platform targeting works but blocked by scratch base incompatibility.	Build Process	Platform OS Version	No	Not Planned	Very High
testDeviceRunEnv	frontend/dockerfile/dockerfile_rundevice_test.go	Linux-Only Concept	Tests CDI (Container Device Interface) device injection into RUN commands with vendor-specific device environment variables. CDI is Linux-specific technology not supported on Windows containers.	Container Runtime	CDI Device Injection	No	Not Planned	Very High
testCopyHeredoc	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests COPY with heredoc syntax using busybox base and Unix commands (adduser -D, stat -c). Heredoc functionality works conceptually but needs Windows-compatible base images and permission handling.	Build Process	Heredoc COPY	Yes	Medium	High
testCopyHeredocSpecialSymbols	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests COPY heredoc with special symbol handling using scratch base. Heredoc parsing supported but blocked by scratch base incompatibility and symbol handling differences.	Build Process	Heredoc COPY	Yes	Medium	High
testRunBasicHeredoc	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests RUN with basic heredoc functionality using busybox and Unix commands (echo, whoami). Heredoc execution model needs Windows shell adaptation and compatible base images.	Build Process	Heredoc RUN	Yes	Medium	High
testRunFakeHeredoc	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests heredoc with custom SHELL (awk) and scratch base. Heredoc functionality present but needs Windows-compatible interpreters and base images instead of scratch.	Build Process	Heredoc SHELL	Yes	Medium	High
testRunShebangHeredoc	frontend/dockerfile/dockerfile_heredoc_test.go	Linux-Only Concept	Tests heredoc with Unix shebang (#!/bin/awk -f) execution using busybox base. Shebang is Unix-specific concept not supported in Windows containers.	Build Process	Heredoc Shebang	No	Low	Very High
testRunComplexHeredoc	frontend/dockerfile/dockerfile_heredoc_test.go	Linux-Only Concept	Tests complex heredoc with Unix file descriptors (/proc/self/fd/3), pipes, and awk processing. File descriptor manipulation and /proc filesystem are Linux-specific.	Build Process	Heredoc Complex	No	Low	Very High
testHeredocIndent	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests heredoc indentation handling (<<EOF vs <<-EOF) with busybox and scratch bases. Indentation processing supported but needs Windows-compatible base images.	Build Process	Heredoc Indentation	Yes	Medium	High
testHeredocVarSubstitution	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests variable substitution in heredoc content using busybox base and Unix commands. Variable expansion works but needs Windows shell syntax adaptation.	Build Process	Heredoc Variables	Yes	Medium	High
testOnBuildHeredoc	frontend/dockerfile/dockerfile_heredoc_test.go	Command Complexity	Tests ONBUILD with heredoc using busybox base and registry operations. ONBUILD heredoc functionality should work with Windows-compatible base images and commands.	Build Process	ONBUILD Heredoc	Yes	Medium	High
testParallelism	solver/jobs_test.go	Command Complexity	Tests BuildKit job parallelism control using busybox base and Unix shell commands (/bin/sh -c, touch, while loops). Core parallelism functionality platform-agnostic but needs Windows-compatible base images and shell syntax.	Container Runtime	Job Parallelism	Yes	Medium	High
testBridgeNetworkingDNSNoRootless	client/client_test.go	Linux-Only Concept	Tests CNI bridge networking with DNS resolution using busybox base and netcat (nc -l) commands. CNI networking is Linux-specific container networking designed for non-Windows platforms.	Container Runtime	CNI Bridge Networking	No	Not Planned	Very High
testExportBusyboxLocal	client/client_test.go	Linux-Only Concept	Tests local export functionality using busybox base image and validating busybox binary presence (/bin/busybox). Uses Linux-specific busybox container not available on Windows platforms.	Build Process	Local Export	No	Low	Very High
testSSHMount	client/client_test.go	Linux-Only Concept	Tests SSH agent socket mounting using SSH agent keyring, RSA key generation, and Unix socket communication. SSH agent integration uses Unix domain sockets not supported on Windows containers.	Security/Permissions	SSH Mounting	No	Low	Very High
testRawSocketMount	client/client_test.go	Linux-Only Concept	Tests Unix domain socket mounting using net.Listen("unix") and curl --unix-socket commands with alpine base. Unix domain sockets are Linux-specific IPC mechanism not available on Windows.	Container Runtime	Unix Socket Mounting	No	Not Planned	Very High
testExtraHosts	client/client_test.go	Command Complexity	Tests extra hosts functionality (/etc/hosts manipulation) using busybox base and Unix commands (cat, grep). Extra hosts feature should work on Windows with compatible base images and Windows hosts file adaptation.	Container Runtime	Extra Hosts	Yes	Medium	High
testShmSize	client/client_test.go	Linux-Only Concept	Tests shared memory size configuration using /dev/shm tmpfs mount and busybox base with mount command validation. Windows containers don't have /dev/shm filesystem or tmpfs mount support.	Container Runtime	Shared Memory	No	Not Planned	Very High
testUlimit	client/client_test.go	Linux-Only Concept	Tests ulimit (user limits) configuration using busybox base and Unix ulimit command to query file descriptor limits. Windows doesn't have ulimit concept - uses different resource limit management through Windows APIs and job objects.	Container Runtime	User Limits	No	Not Planned	Very High
testNetworkMode	client/client_test.go	Linux-Only Concept	Tests network isolation modes (NetModeNone, NetModeHost) using busybox base with wget and ifconfig commands. Network isolation models are Linux-specific container networking concepts.	Container Runtime	Network Isolation	No	Not Planned	Very High
testSecurityMode	client/client_test.go	Linux-Only Concept	Tests container security modes (SecurityModeSandbox, SecurityModeInsecure) using busybox base and Linux capabilities inspection (/proc/self/status, CapEff). Linux capabilities and /proc filesystem are Unix-specific security concepts.	Security/Permissions	Security Modes	No	Not Planned	Very High
testSecurityModeSysfs	client/client_test.go	Linux-Only Concept	Tests security mode with sysfs filesystem access using Linux-specific filesystem checks. Sysfs (/sys) is Linux kernel virtual filesystem for device and driver information not available on Windows.	Security/Permissions	Security Modes Sysfs	No	Not Planned	Very High
testSecurityModeErrors	client/client_test.go	Linux-Only Concept	Tests security mode error handling and entitlement validation using busybox base. Security entitlement system designed around Linux container security models and capabilities framework.	Security/Permissions	Security Mode Errors	No	Not Planned	Very High
testSecretMounts	client/client_test.go	Command Complexity	Tests secret file mounting using busybox base and Unix commands (mount, grep, cat, test). Core secret mounting functionality should work on Windows with tmpfs adaptation and Windows-compatible validation commands.	Security/Permissions	Secret File Mounts	Yes	High	High
testSecretEnv	client/client_test.go	Command Complexity	Tests secret environment variable injection using busybox base and Unix shell syntax (sh -c, ${VAR} expansion). Secret environment injection should work on Windows with Windows shell syntax adaptation.	Security/Permissions	Secret Environment Variables	Yes	High	Medium
testBuildExportZstd	client/client_test.go	Command Complexity	Tests zstd compression in OCI export using busybox base and Unix commands (sh -e -c). OCI exporter and zstd compression are supported on Windows, needs Windows-compatible base image and shell commands.	Build Process	OCI Export Zstd	Yes	High	Medium
testPullZstdImage	client/client_test.go	Command Complexity	Tests zstd-compressed image registry round-trip using busybox base and Unix commands (sh -e -c). Core functionality (image export, registry push/pull, zstd compression, OCI export) supported on Windows, needs Windows-compatible base image and shell commands.	Build Process	Zstd Image Registry	Yes	High	Medium
testBasicS3CacheImportExport	client/client_test.go	Conversion Issues	Tests S3 cache backend using MinIO server requiring minio and mc binaries in PATH. Core S3 cache functionality supported on Windows but test setup requires minio/mc executables typically not available on Windows.	Cache Management	S3 Cache Backend	Yes	Medium	High
testBasicAzblobCacheImportExport	client/client_test.go	Conversion Issues	Tests Azure Blob cache backend using Azurite server requiring azurite-blob binary in PATH. Core Azure Blob cache functionality supported on Windows but test setup requires azurite executable not typically available on Windows.	Cache Management	Azure Blob Cache	Yes	Medium	High
testSnapshotWithMultipleBlobs	client/client_test.go	Command Complexity	Tests OCI export with multiple blob snapshots using OCI exporter feature. OCI exporter supported on Windows (confirmed earlier), needs Windows-compatible base images and commands for comprehensive testing.	Build Process	OCI Multiple Blobs	Yes	Medium	Medium
testMoveParentDir	client/client_test.go	Command Complexity	Tests directory movement operations using busybox base and OCI exporter. Core file operation functionality should work on Windows with Windows-compatible base images and path handling adaptations.	File System	Directory Operations	Yes	Medium	High
testReadonlyRootFS	client/client_test.go	Linux-Only Concept	Tests read-only root filesystem capability using llb.ReadonlyRootFS() and busybox base with Unix commands (/bin/touch). Read-only filesystem concept doesn't apply to Windows containers which use different security models.	Container Runtime	Read-only Root FS	No	Not Planned	Very High
testMountStubsDirectory	client/client_test.go	Command Complexity	Tests mount stub directory cleanup using busybox base, Unix commands (touch), and tmpfs mounts. Core mount stub management should work on Windows with Windows-compatible base images, commands, and mount types.	File System	Mount Stub Cleanup	Yes	Medium	High
testMountStubsTimestamp	client/client_test.go	Command Complexity	Tests timestamp preservation for mount stubs using busybox base and Unix touch command with --date option. Core timestamp functionality should work on Windows but requires PowerShell-based timestamp manipulation instead of Unix touch.	File System	Mount Stub Timestamps	Yes	Low	Very High
testLLBMountPerformance	client/client_test.go	Flaky on Windows	Performance test with timeouts that may be insufficient for Windows container startup overhead. Test has adaptive timeouts but may need Windows-specific adjustments. Shows good cross-platform test design with busybox vs Windows base image selection.	Performance	RUN Mount	Yes	Not Planned	Low
testLayerLimitOnMounts	client/client_test.go	Linux-Only Concept	Creates 110 layers then tests mounting with readonly flag. Requires runc's rootfs directory handling - runc mounts all layers to a physical 'rootfs' directory path in the bundle. Windows containerd executor uses direct mount abstractions without requiring rootfs directory paths, making this incompatible.	Container Runtime	RUN Mount layerLimit	No	Not Planned	Very High

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Previously Skipped Tests Now Working on Windows

These tests were previously skipped on Windows but have been fixed either through source code modifications or by removing unnecessary skip conditions. They now pass successfully on Windows.

Test Name	File Path	Previous Skip Reason	Fix Type	Fix Description	BuildKit Feature	Commit/PR	Impact
testRefReadFile	frontend/frontend_test.go	Platform assumption	Unnecessary Skip	Test functionality was already cross-platform compatible. Frontend file reading operations work identically on Windows.	Frontend File Reading	Latest	Medium
testRefReadDir	frontend/frontend_test.go	Platform assumption	Unnecessary Skip	Directory listing operations are cross-platform compatible in BuildKit frontend.	Frontend Directory Operations	Latest	Medium
testRefStatFile	frontend/frontend_test.go	Platform assumption	Unnecessary Skip	File stat operations work cross-platform through BuildKit's filesystem abstraction layer.	Frontend File Statistics	Latest	Medium
testRefEvaluate	frontend/frontend_test.go	Platform assumption	Unnecessary Skip	Frontend evaluation logic is platform-agnostic and works identically on Windows.	Frontend Evaluation	Latest	Medium
testErrorsSourceMap	frontend/dockerfile/errors_test.go	Platform assumption	Unnecessary Skip	Error source mapping functionality is platform-independent and works on Windows.	Error Source Mapping	Latest	Low
testTargetsList	frontend/dockerfile/dockerfile_targets_test.go	Platform assumption	Source Code Fix	Dockerfile target listing required Windows-compatible target resolution and parsing logic.	Build Target Listing	Latest	Medium
testOutlineRecursiveArgs	frontend/dockerfile/dockerfile_outline_test.go	Platform assumption	Unnecessary Skip	Dockerfile outline parsing with recursive argument resolution works cross-platform without modification.	Dockerfile Outline Parsing	Latest	Medium
testAddChecksum	frontend/dockerfile/dockerfile_addchecksum_test.go	Platform assumption	Source Code Fix	ADD checksum validation required Windows-compatible checksum computation and validation logic.	ADD Checksum Validation	Latest	High
testEmptyStringArgInEnv	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Environment variable argument handling required Windows-specific environment variable processing.	ENV Argument Processing	Latest	Low
testExportCacheLoop	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Cache export loop detection logic required Windows-compatible cache management and validation.	Cache Export Validation	Latest	Medium
testExportedHistoryFlattenArgs	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Image history export with argument flattening required Windows-compatible history processing.	Image History Export	Latest	Low
testAddInvalidChmod	frontend/dockerfile/dockerfile_test.go	Platform assumption	Unnecessary Skip	Invalid chmod error handling works cross-platform as it tests error validation, not actual chmod functionality.	ADD Error Validation	Latest	Medium
testFrontendInputs	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Frontend input processing required Windows-compatible input validation and processing logic.	Frontend Input Processing	Latest	Medium
testStepNames	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Build step naming functionality required Windows-compatible step name generation and validation.	Build Step Management	Latest	Low
testBaseImagePlatformMismatch	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Platform mismatch detection required Windows platform validation logic.	Platform Validation	Latest	High
testMaintainBaseOSVersion	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	OS version maintenance logic required Windows-specific OS version handling.	OS Version Management	Latest	High
testTargetMistype	frontend/dockerfile/dockerfile_test.go	Platform assumption	Source Code Fix	Build target validation required Windows-compatible target parsing and error handling.	Build Target Validation	Latest	Low
testSourceDateEpochImageExporter	client/client_test.go	Platform assumption	Source Code Fix	SOURCE_DATE_EPOCH support required Windows-compatible timestamp handling in image exporters.	Reproducible Builds	Latest	High
testBuildExportWithForeignLayer	client/client_test.go	Platform assumption	Source Code Fix	Foreign layer handling required Windows-compatible layer management and export logic.	Foreign Layer Export	Latest	High
testBasicRegistryCacheImportExport	client/client_test.go	Platform assumption	Source Code Fix	Registry cache operations required Windows-compatible cache backend implementation.	Registry Cache	Latest	High
testMultipleRegistryCacheImportExport	client/client_test.go	Platform assumption	Source Code Fix	Multiple registry cache backends required Windows-compatible multi-backend handling.	Registry Cache Multiple	Latest	High
testRmSymlink	client/client_test.go	Platform assumption	Source Code Fix	Symlink removal operations required Windows symlink handling instead of Unix symlink assumptions.	Symlink Operations	Latest	Medium
testMultipleCacheExports	client/client_test.go	Platform assumption	Source Code Fix	Multiple cache export functionality required Windows-compatible export coordination.	Cache Export Multiple	Latest	Medium
testClientGatewayEmptyImageExec	client/build_test.go	Platform assumption	Unnecessary Skip	Empty image execution error handling works cross-platform as it tests gateway error handling, not platform-specific execution.	Gateway Empty Image	Latest	Medium
testUsage	cmd/buildctl/buildctl_test.go	Platform assumption	Unnecessary Skip	buildctl usage help is platform-independent CLI functionality that works identically on Windows.	CLI Usage	Latest	Low
testPrune	cmd/buildctl/prune_test.go	Platform assumption	Unnecessary Skip	buildctl prune operations work identically across platforms without modification.	CLI Prune	Latest	Medium
testDiskUsage	cmd/buildctl/diskusage_test.go	Platform assumption	Unnecessary Skip	Disk usage reporting functionality is platform-agnostic and works on Windows without changes.	CLI Disk Usage	Latest	Medium
testBuildWithLocalFiles	cmd/buildctl/build_test.go	Platform assumption	Source Code Fix	Local file building required Windows path handling and file system operations.	CLI Build Local	Latest	High
testBuildLocalExporter	cmd/buildctl/build_test.go	Platform assumption	Source Code Fix	Local export functionality required Windows-compatible file export operations.	CLI Export Local	Latest	High
testBuildContainerdExporter	cmd/buildctl/build_test.go	Platform assumption	Source Code Fix	Containerd export functionality required Windows containerd worker compatibility.	CLI Export Containerd	Latest	High
testBuildMetadataFile	cmd/buildctl/build_test.go	Platform assumption	Source Code Fix	Build metadata file generation required Windows file system and path handling.	CLI Metadata Export	Latest	Medium
testUncompressedRegistryCacheImportExport	client/client_test.go	Platform assumption	Source Code Fix	Uncompressed registry cache operations required Windows-compatible cache compression handling.	Registry Cache Uncompressed	Latest	High

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Windows-Compatible Tests Failing in GitHub Actions

These tests have been modified to work on Windows locally but still fail in the GitHub Actions CI environment due to infrastructure, timing, or environment-specific issues.

Test Name	File Path	Local Status	CI Failure Type	Failure Description	Root Cause	BuildKit Feature	Fix Complexity	Priority
testOnBuildNamedContext	frontend/dockerfile/dockerfile_test.go	Passes	Environment	ONBUILD with named context handling fails due to OCI layout export path differences in CI environment	Windows path handling in OCI export + temp directory permissions in GitHub Actions	ONBUILD + Named Context	Medium	High
testOnBuildInheritedStageRun	frontend/dockerfile/dockerfile_test.go	Passes	Environment	ONBUILD inheritance across build stages fails due to stage state management in CI	CI environment stage isolation + Windows container state persistence	ONBUILD Inheritance	Medium	High
testOnBuildInheritedStageWithFrom	frontend/dockerfile/dockerfile_test.go	Passes	Environment	ONBUILD inheritance with FROM directive fails in CI container setup	Stage context switching + Windows container runtime timing in CI	ONBUILD + Multi-stage	Medium	High
testOnBuildWithCacheMount	frontend/dockerfile/dockerfile_test.go	Passes	Resource	ONBUILD with cache mount fails due to cache directory permissions in CI environment	GitHub Actions Windows runner cache mount permissions + container isolation	ONBUILD + Cache Mount	High	High
testImageManifestCacheImportExport	frontend/dockerfile/dockerfile_test.go	Passes	Network	Image manifest cache import/export fails due to CI network timing/bandwidth issues	CI network constraints + Windows container registry communication delays	Cache Import/Export	Medium	Medium
testCacheImportExport	frontend/dockerfile/dockerfile_test.go	Passes	Resource	Basic cache import/export fails due to disk I/O timing or permissions in CI	GitHub Actions Windows runner disk I/O performance + temp directory handling	Cache Management	Medium	High
testImportExportReproducibleIDs	frontend/dockerfile/dockerfile_test.go	Passes	Environment	Reproducible build ID generation fails due to CI environment differences	CI environment variables + Windows time/entropy differences affecting build IDs	Reproducible Builds	Low	Medium
testNoCache	frontend/dockerfile/dockerfile_test.go	Passes	Resource	No-cache build fails due to CI resource constraints or timing	GitHub Actions resource limits + Windows container memory/CPU constraints	Cache Disable	Low	Low
testNamedImageContextTimestamps	frontend/dockerfile/dockerfile_test.go	Passes	Timing	Named image context timestamp validation fails due to CI filesystem timing	Windows filesystem timestamp precision + CI environment clock synchronization	Named Context	Low	Medium
testNamedInputContext	frontend/dockerfile/dockerfile_test.go	Passes	Environment	Named input context handling fails due to CI path resolution differences	Windows path resolution + CI temporary directory structure differences	Named Context	Medium	Medium
testZstdLocalCacheExport	client/client_test.go	Passes	Compression	Zstd compression cache export fails due to Windows containerd zstd support in CI	CI Windows containerd version lacking full zstd compression support	Cache Export + Zstd	High	High
testZstdLocalCacheImportExport	client/client_test.go	Passes	Compression	Zstd cache import/export fails due to OCI mediatype + containerd applier issues in CI	GitHub Actions containerd version incompatibility with zstd+oci-mediatypes combination	Cache + Zstd + OCI	High	High
testZstdRegistryCacheImportExport	client/client_test.go	Passes	Network	Zstd registry cache fails due to CI registry communication + compression issues	CI network + registry bandwidth limitations with zstd compression overhead	Registry Cache + Zstd	Medium	Medium
testSessionExporter	client/client_test.go	Passes	Resource	Session-based OCI export fails due to CI session management or file handle limits	GitHub Actions Windows session isolation + file handle/resource limits during OCI export	Session Export + OCI	Medium	High

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