/usr/lib/pkgconfig/libsidplay2.pc is in libsidplay2-dev 2.1.1-14ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 | prefix=/usr
exec_prefix=${prefix}
libdir=${prefix}/lib
includedir=${prefix}/include
builders=${prefix}/lib/
Name: libsidplay
Description: C64 cycle exact stereo sidplayer library.
Version: 2.1.1
Libs: -L${libdir} -lsidplay2
Cflags: -DHAVE_UNIX -I${includedir}
|