gh-119729: Use 't' in pkg-config file name for free-threaded build (#119738)

For example, the free-threaded build now generates
`lib/pkgconfig/python-3.13t.pc` and the debug build generates
`lib/pkgconfig/python-3.13d.pc`.

Author: colesbury

Doc/whatsnew/3.13.rst

@@ -2181,6 +2181,10 @@ Build Changes
   The bundled mimalloc has custom changes, see :gh:`113141` for details.
   (Contributed by Dino Viehland in :gh:`109914`.)
 
+* On POSIX systems, the pkg-config (``.pc``) filenames now include the ABI
+  flags.  For example, the free-threaded build generates ``python-3.13t.pc``
+  and the debug build generates ``python-3.13d.pc``.
+
 
 Porting to Python 3.13
 ======================

Makefile.pre.in

@@ -40,6 +40,7 @@ LINKCC=		@LINKCC@
 AR=		@AR@
 READELF=	@READELF@
 SOABI=		@SOABI@
+ABIFLAGS=	@ABIFLAGS@
 LDVERSION=	@LDVERSION@
 MODULE_LDFLAGS=@MODULE_LDFLAGS@
 GITVERSION=	@GITVERSION@
@@ -150,7 +151,6 @@ INCLUDEDIR=	@includedir@
 CONFINCLUDEDIR=	$(exec_prefix)/include
 PLATLIBDIR=	@PLATLIBDIR@
 SCRIPTDIR=	$(prefix)/$(PLATLIBDIR)
-ABIFLAGS=	@ABIFLAGS@
 # executable name for shebangs
 EXENAME=	$(BINDIR)/python$(LDVERSION)$(EXE)
 # Variable used by ensurepip
@@ -2262,10 +2262,10 @@ bininstall: commoninstall altbininstall
 	-if test "$(VERSION)" != "$(LDVERSION)"; then \
 		rm -f $(DESTDIR)$(BINDIR)/python$(VERSION)-config; \
 		(cd $(DESTDIR)$(BINDIR); $(LN) -s python$(LDVERSION)-config python$(VERSION)-config); \
-		rm -f $(DESTDIR)$(LIBPC)/python-$(LDVERSION).pc; \
-		(cd $(DESTDIR)$(LIBPC); $(LN) -s python-$(VERSION).pc python-$(LDVERSION).pc); \
-		rm -f $(DESTDIR)$(LIBPC)/python-$(LDVERSION)-embed.pc; \
-		(cd $(DESTDIR)$(LIBPC); $(LN) -s python-$(VERSION)-embed.pc python-$(LDVERSION)-embed.pc); \
+		rm -f $(DESTDIR)$(LIBPC)/python-$(VERSION).pc; \
+		(cd $(DESTDIR)$(LIBPC); $(LN) -s python-$(LDVERSION).pc python-$(VERSION).pc); \
+		rm -f $(DESTDIR)$(LIBPC)/python-$(VERSION)-embed.pc; \
+		(cd $(DESTDIR)$(LIBPC); $(LN) -s python-$(LDVERSION)-embed.pc python-$(VERSION)-embed.pc); \
 	fi
 	-rm -f $(DESTDIR)$(BINDIR)/python3-config
 	(cd $(DESTDIR)$(BINDIR); $(LN) -s python$(VERSION)-config python3-config)
@@ -2702,8 +2702,8 @@ libainstall: all scripts
 	$(INSTALL_DATA) Modules/Setup.bootstrap $(DESTDIR)$(LIBPL)/Setup.bootstrap
 	$(INSTALL_DATA) Modules/Setup.stdlib $(DESTDIR)$(LIBPL)/Setup.stdlib
 	$(INSTALL_DATA) Modules/Setup.local $(DESTDIR)$(LIBPL)/Setup.local
-	$(INSTALL_DATA) Misc/python.pc $(DESTDIR)$(LIBPC)/python-$(VERSION).pc
-	$(INSTALL_DATA) Misc/python-embed.pc $(DESTDIR)$(LIBPC)/python-$(VERSION)-embed.pc
+	$(INSTALL_DATA) Misc/python.pc $(DESTDIR)$(LIBPC)/python-$(LDVERSION).pc
+	$(INSTALL_DATA) Misc/python-embed.pc $(DESTDIR)$(LIBPC)/python-$(LDVERSION)-embed.pc
 	$(INSTALL_SCRIPT) $(srcdir)/Modules/makesetup $(DESTDIR)$(LIBPL)/makesetup
 	$(INSTALL_SCRIPT) $(srcdir)/install-sh $(DESTDIR)$(LIBPL)/install-sh
 	$(INSTALL_SCRIPT) python-config.py $(DESTDIR)$(LIBPL)/python-config.py

Misc/NEWS.d/next/Build/2024-05-29-17-40-50.gh-issue-119729.k0xJ5U.rst

@@ -0,0 +1,5 @@
+On POSIX systems, the pkg-config (``.pc``) filenames now include the ABI
+flags, which may include debug ("d") and free-threaded ("t").  For example:
+* ``python-3.14.pc`` (default, non-debug build)
+* ``python-3.14d.pc`` (default, debug build)
+* ``python-3.14t.pc`` (free-threaded build)