I have a Jenkins job which builds GHC on armhf and just got this:

rts/Linker.c:6209:21: error:
     error: ‘target_shndx’ undeclared (first use in this function)
        if (oc->sections[target_shndx].kind == SECTIONKIND_OTHER) {
                         ^

rts/Linker.c:6209:21: error:
     note: each undeclared identifier is reported only once for each
     function it appears in
     `gcc' failed in phase `C Compiler'. (Exit code: 1)

Seems this is a result of 04e83666 and the fix is pretty obvious.