lang/rexx-regina: Linux/NetBSD build inconsistency

["Periklis Akritidis" <periklis%akritidis.org@localhost>]

I'm encountering a build inconsistency with lang/rexx-regina on different platforms.
On Linux, the build produces libregina.so.3.9 with symlinks libregina.so and libregina.so.3,
while on NetBSD 9.x, only libregina.so is created. As the shipped PLIST only includes libregina.so,
this discrepancy causes breakage on Linux.

Below is a patch, but I am looking for a more appropriate solution, because it feels wrong to make
the PLIST conditional on the OS when it might be a toolchain issue. I am using the system toolchain.

Any advice on how to best resolve this would be greatly appreciated,
otherwise I will research this a bit deeper before sharing a final patch.

PS. I also hesitate to hardcode the version numbers since there is PKGVERSION,
but I see most packages hardcode the partial versions of .so links in the PLIST.

lang/rexx-regina$ cvs diff -u
cvs diff: Diffing .
Index: Makefile
===================================================================
RCS file: /cvsroot/pkgsrc/lang/rexx-regina/Makefile,v
retrieving revision 1.16
diff -u -r1.16 Makefile
--- Makefile    2 Apr 2024 18:08:37 -0000       1.16
+++ Makefile    5 Dec 2024 01:37:43 -0000
@@ -29,6 +29,14 @@
 REPLACE.regina.new=    ${PREFIX}/bin/regina
 REPLACE_FILES.regina=  demo/*.rexx regutil/*.rexx
 
+.include "../../mk/bsd.prefs.mk"
+
+PLIST_VARS+=           linux
+
+.if ${OPSYS} == "Linux"
+PLIST.linux=           yes
+.endif
+
 SUBST_CLASSES+=                etc
 SUBST_STAGE.etc=       pre-configure
 SUBST_MESSAGE.etc=     Fixing etc directory path
Index: PLIST
===================================================================
RCS file: /cvsroot/pkgsrc/lang/rexx-regina/PLIST,v
retrieving revision 1.3
diff -u -r1.3 PLIST
--- PLIST       2 Apr 2024 18:08:37 -0000       1.3
+++ PLIST       5 Dec 2024 01:37:43 -0000
@@ -7,6 +7,8 @@
 include/rexxsaa.h
 lib/libregina.a
 lib/libregina.so
+${PLIST.linux}lib/libregina.so.3
+${PLIST.linux}lib/libregina.so.3.9
 lib/pkgconfig/libregina.pc
 lib/regina-rexx/${PKGVERSION}/libregutil.so
 lib/regina-rexx/${PKGVERSION}/librxtest1.so
cvs diff: Diffing patches