Library directory missing in pkg-config files

[Michał Liszcz]

Hi,

I'm using 6.3.20211021. I configured ncurses with a custom --prefix, I also
specified --enable-pc-files and --with-pkg-config-libdir pointing to some
directory inside the installation prefix.

Below is a generated pkg-config file installed into prefix:

 # pkg-config file generated by gen-pkgconfig
 # vile:makemode

 prefix=prefix-ncurses
 exec_prefix=${prefix}
 libdir=${exec_prefix}/lib
 includedir=${prefix}/include/ncurses
 abi_version=6
 major_version=6
 version=6.3.20211021

 Name: ncurses
 Description: ncurses 6.3 library
 Version: ${version}
 URL: https://invisible-island.net/ncurses
 Requires.private:
 Libs: -lncurses -ltinfo
 Libs.private:
 Cflags:  -D_GNU_SOURCE -I${includedir} -I/prefix-ncurses/include

I am not able to link my application with ncurses because the custom library
directory is not exposed to pkg-config, i.e. this commands:

 env PKG_CONFIG_PATH=/prefix-ncurses/pkgconfig pkg-config --libs ncurses

Prints:

 -lncurses -ltinfo

While I think it should print:

 -L/prefix-ncurses/lib -lncurses -ltinfo

I managed to fix this locally by changing misc/gen-pkgconfig.in:

 - Libs: $lib_flags $LIBS
 + Libs: -L$show_libdir $lib_flags $LIBS

Could you please consider changing gen-pkgconfig.in as proposed above?

Thanks,
Michal