The current libmpc package links against old versions of gmp and mpfr. Gcc 4.9 bootstrap links against the new gmp and mpfr (and libmpc).
The resulting linker warning confuses gcc's configure script, disables Ada and breaks the build. --- Step one is to bump mpc and update WANTLIB for good measure Index: Makefile =================================================================== RCS file: /home/vcs/cvs/openbsd/ports/devel/libmpc/Makefile,v retrieving revision 1.8 diff -u -p -r1.8 Makefile --- Makefile 16 Mar 2015 18:07:42 -0000 1.8 +++ Makefile 15 Nov 2016 16:37:22 -0000 @@ -5,7 +5,7 @@ COMMENT= complex numbers math library V= 0.9 DISTNAME= mpc-${V} PKGNAME= libmpc-${V} -REVISION= 1 +REVISION= 2 SHARED_LIBS= mpc 0.1 # 2.0 CATEGORIES= devel math @@ -18,7 +18,7 @@ PERMIT_PACKAGE_CDROM= Yes LIB_DEPENDS= devel/mpfr \ devel/gmp -WANTLIB= mpfr>=1.0 gmp>=9.0 m +WANTLIB= mpfr>=1.2 gmp>=10.0 m CONFIGURE_STYLE= gnu CONFIGURE_ARGS= --with-mpfr=${LOCALBASE} \