graphics/cairo compile error

[David Newman]

On 10.3-RELEASE on amd64, the graphics/cairo port fails to compile with
the error pasted below.

On previous systems where I've built cairo, I haven't needed to set
MAKE_JOBS_UNSAFE=yes. Is there another workaround?

Thanks!

dn

===>   cairo-1.14.6,2 depends on package: pkgconf>=0.9.10 - found
===>   cairo-1.14.6,2 depends on package: libGL>0 - not found
===>   libGL-11.1.2 depends on executable: makedepend - found
===>   libGL-11.1.2 depends on package: libclc>=0.0.r222830 - not found
===>   libclc-0.2.0.20151006 depends on executable: clang37 - not found
===>  Building for llvm37-3.7.1_2
[9/2965] Building X86GenAsmMatcher.inc...
[10/2965] Building X86GenDAGISel.inc...
FAILED: lib/Target/X86/X86GenDAGISel.inc.tmp
cd /usr/ports/devel/llvm37/work/.build/lib/Target/X86 &&
/usr/ports/devel/llvm37/work/.build/bin/llvm-tblgen -gen-dag-isel -I
/usr/ports/devel/llvm37/work/llvm-3.7.1.src/lib/Target/X86 -I
/usr/ports/devel/llvm37/work/llvm-3.7.1.src/lib/Target -I
/usr/ports/devel/llvm37/work/llvm-3.7.1.src/include
/usr/ports/devel/llvm37/work/llvm-3.7.1.src/lib/Target/X86/X86.td -o
/usr/ports/devel/llvm37/work/.build/lib/Target/X86/X86GenDAGISel.inc.tmp
[11/2965] Building X86GenAsmMatcher.inc...
ninja: build stopped: subcommand failed.
===> Compilation failed unexpectedly.
Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure to
the maintainer.
*** Error code 1