libarchive proides a broken .pc file

[kjmeagher]

I am trying to compile my own program that depends on libarchive in an environment that where libarchive is provided by spack on centos7 but running into problems. My spack install uses libarchive-3.7.6-by477lvw2ko7sg6s7k2ibx5omyniloxn which provides lib/pkgconfig/libarchive.pc

prefix=/home/kmeagher/spack/opt/spack/linux-centos7-zen3/gcc-13.3.0/libarchive-3.7.6-by477lvw2ko7sg6s7k2ibx5omyniloxn
exec_prefix=${prefix}
libdir=${exec_prefix}/lib
includedir=${prefix}/include

Name: libarchive
Description: library that can create and read several streaming archive formats
Version: 3.7.6
Cflags: -I${includedir}
Cflags.private: -DLIBARCHIVE_STATIC
Libs: -L${libdir} -larchive
Libs.private: -lcrypto -llzo2 -llzma -lzstd -llz4 -lbz2  -lz -L/home/kmeagher/spack/opt/spack/linux-centos7-zen3/gcc-13.3.0/libxml2-2.13.5-mmxcwm2zws5yv2zoaeciosby4wuqhlt7/lib -lxml2
Requires.private: iconv libcrypto

but iconv doesn't provide a .pc file so that when I try to use pkg-config i get an error

pkg-config --cflags libarchive
Package iconv was not found in the pkg-config search path.
Perhaps you should add the directory containing `iconv.pc'
to the PKG_CONFIG_PATH environment variable
Package 'iconv', required by 'libarchive', not found