babbaj@nixos:~ ❯ nix build nixpkgs#gbenchmark
babbaj@nixos:~ ❯ cat result/lib/pkgconfig/benchmark.pc
prefix=/nix/store/yf25swipsphj343waql8pf2qszg65wjs-gbenchmark-1.6.1
exec_prefix=${prefix}
libdir=${prefix}//nix/store/yf25swipsphj343waql8pf2qszg65wjs-gbenchmark-1.6.1/lib
includedir=${prefix}//nix/store/yf25swipsphj343waql8pf2qszg65wjs-gbenchmark-1.6.1/include

Name: benchmark
Description: Google microbenchmark framework
Version: 1.6.1

Libs: -L${libdir} -lbenchmark
Libs.private: -lpthread
Cflags: -I${includedir}