pkg/55539: pkgsrc graphviz-2.44.1 fails too build - failure to expand make variable?

[thorpej%me.com@localhost]

>Number:         55539
>Category:       pkg
>Synopsis:       pkgsrc graphviz-2.44.1 fails too build - failure to expand make variable?
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Aug 04 14:50:00 +0000 2020
>Originator:     Jason Thorpe
>Release:        NetBSD 9.99.69 - pkgsrc trunk from Aug 3 2020
>Organization:
RISCy Business
>Environment:
NetBSD stinky 9.99.69 NetBSD 9.99.69 (GENERIC) #0: Mon Aug  3 06:30:00 UTC 2020  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
graphviz-2.44.1 build gets stuck with an apparent failure to expand a make variable.  This may be a recent regression in make?

===> Building for graphviz-2.44.1
touch /home/nbsd/pkgsrc/graphics/graphviz/work/graphviz-2.44.1/Makefile /home/nbsd/pkgsrc/graphics/graphviz/work/graphviz-2.44.1/graphviz_version.h
/usr/bin/make  all-recursive
Making all in libltdl
/usr/bin/make  all-am
Making all in lib
Making all in cdt
groff -Tps -man  >cdt.3.ps

>How-To-Repeat:
Attempt to build graphviz-2.44.1 from pkgsrc-current on the Aug 03 NetBSD daily build of NetBSD/amd64.
>Fix:
"USE_TOOLS+= gmake" works around the problem. (Must do a "make clean" first.)