GCC 7.1 build error

[BERTRAND Joël <joel.bertrand%systella.fr@localhost>]

	Hello,

	I'm trying to obtain a usable fortran compiler on a AXP workstation 
running NetBSD 8.0. In pkgsrc (2017Q2), I have found gcc-7.1.

System :
einstein:[~] > uname -a
NetBSD einstein.systella.fr 8.0_BETA NetBSD 8.0_BETA (GENERIC-$Revision: 
1.375 $) #0: Tue Jul 11 02:14:42 CEST 2017 
bertrand@rayleigh:/export/home/bertrand/netbsd/netbsd-cross/netbsd-8/obj-axp-ev56/sys/arch/alpha/compile/GENERIC 
alpha
(Digital Personal WorkStation 500au, 500MHz, s/n)

	After a very long time, build process aborts in stage2 when it tries to 
compile openmp with following error :

gmake[5]: Entering directory 
'/usr/pkgsrc/lang/gcc7/work/build/alpha--netbsd/libgomp'
/bin/sh ./libtool --tag=FC   --mode=compile 
/usr/pkgsrc/lang/gcc7/work/build/./gcc/gfortran 
-B/usr/pkgsrc/lang/gcc7/work/build/./gcc/ 
-B/usr/pkg/gcc7/alpha--netbsd/bin/ -B/usr/pkg/gcc7/alpha--netbsd/lib/ 
-isystem /usr/pkg/gcc7/alpha--netbsd/include -isystem 
/usr/pkg/gcc7/alpha--netbsd/sys-include     -L. -Wall -L../libgfortran 
-c -o openacc.lo ../../../gcc-7.1.0/libgomp/openacc.f90
libtool: compile:  /usr/pkgsrc/lang/gcc7/work/build/./gcc/gfortran 
-B/usr/pkgsrc/lang/gcc7/work/build/./gcc/ 
-B/usr/pkg/gcc7/alpha--netbsd/bin/ -B/usr/pkg/gcc7/alpha--netbsd/lib/ 
-isystem /usr/pkg/gcc7/alpha--netbsd/include -isystem 
/usr/pkg/gcc7/alpha--netbsd/sys-include -L. -Wall -L../libgfortran -c 
../../../gcc-7.1.0/libgomp/openacc.f90  -fPIC -o .libs/openacc.o
../../../gcc-7.1.0/libgomp/openacc.f90:139:24:

       integer (c_int32_t) len
                        1
Error: Kind -2 not supported for type INTEGER at (1)
../../../gcc-7.1.0/libgomp/openacc.f90:146:24:

       integer (c_int64_t) len
                        1
Error: Kind -2 not supported for type INTEGER at (1)
../../../gcc-7.1.0/libgomp/openacc.f90:157:24:

       integer (c_int32_t) len
                        1
....

	I haven't found similar issue in mailing list. Is there a chance to 
build gcc 7.1 under NetBSD AXP ?

	Best regards,

	JKB