[tlbuild] asy2.42

[Karl Berry]

    I didn't know we even had a target "make test".

Indeed, you don't have an explicit target "test". But (GNU) make defines
an implicit target foo if it can find a compilable source foo.c[c] (or
foo.p or foo.whatever -- there's a long list). Which it does because of
your vpath declaration.

    Making test a synonym for check doesn't inhibit the compilation of
    this file 

An explicit definition of a test target should override the implicit
definition.

    but making swapping the roles of check and test
    surprisingly works.

I don't understand, but it is strongly desirable for "make check"
to behave as it always has, i.e., to run the test suite. "check" is the
standard target name in the GNU/autotools world. (I wish rms had chosen
"test" instead, but he didn't.)

Rename the prc/test.cc file would also get rid of the
weirdness. --thanks, k.