Gentoo Ebuild - Multilib Strict - need lib64 as a libdir under /usr

[Nheghathivhistha]

Hello,
I am trying to adapt Gentoo's fpc-3.0.4 ebuild file for FPC version 3.2.0.
There were only a cosmetic changes needed but there is one blocking problem, Gentoo's multilib strict check.

The message from Portage is:
Files matching a file type that is not allowed:
   usr/lib/libpas2jslib.so
 * ERROR: dev-lang/fpc-3.2.0::x-portage failed:
 *   multilib-strict check failed!

I have to change FPC's LIBDIR for x86_64 build to "lib64" from "lib" in source files and do not know where to do it.
Could you please tell me what Makefile or other file is the main configuration file for it?
I was playing with Makefile and install/install.sh file in the fpcbuild-3.2.0 directory what not changed the result of target library folder name.

Thank you in advance.

[Nheghathivhistha]

Found

ifdef UNIXHier
INSTALL_LIBDIR:=$(INSTALL_PREFIX)/lib

lines in the Makefile file in the fpc-3.2.0 folder.
Will try to use INSTALL_LIBDIR in the ebuild.

[Nheghathivhistha]

Now it built with libpas2jslib.so file and fpc/3.2.0/fpmkinst/, ide/, source/ and units/ folders under /usr/lib64/ folder,
but there is still /usr/lib/fpc/3.2.0 folder with msg/ and units/ subfolders and ppcx64 and samplecfg files
I can't get moved under /usr/lib64.
I tried INSTALL_SHAREDDIR=/usr/lib64 and FPCDIR=/usr/lib64/fpc/3.2.0 with no success.

Have I to use other INSTALL_ prefixed variables please, like INSTALL_UNITDIR?

[Nheghathivhistha]

It seems that Gentoo's multilib strict check is satisfied using
INSTALL_LIBDIR="${ED}"/usr/lib64 in the ebuild file.
Other files and folders remaining in /usr/lib/fpc (units/, sources/, ppcx64 etc.) not triggers it.
I will finish the ebuild extending it by a few if/fi for i386/x86_64 and ask Gentoo developers for feedback. (Even gcc is having executable files inside /usr/lib/gcc tree at my pure 64 bit system. So my bad feeling about it is most probably my bad understanding of the philosophy around it. )