It occurred to me that Steven M. Bellovin wrote in gmane.os.netbsd.devel.pkgsrc.user:
>> This warning means that somewhere in the build process, the C compiler 
>> is executed. The file work/.work.log should contain a log entry of that. 
>> When, with what command line arguments and (most important) why is the C 
>> compiler run?
>> 
> It isn't run, at least not according to that file:

Just an idea: Does it come with a GNU autoconf script? I've seen configure
scripts that check for cc (And even fail if it doesn't exist), but don't use
it after that. wip/nzbget was a fine example.