Hi,

"pkglint -e -Wall" says


  WARN: Makefile:17: Permission [a] requested for USE_LANGUAGES, but only
  [s] is allowed.

        The available permissions are:
                a       append something using +=
                d       set a default value using ?=
                s       set a variable using :=, =, !=
                p       use a variable during preprocessing
                u       use a variable at runtime

        A "?" means that it is not yet clear which permissions are allowed
        and which aren't.

Is this warning for USE_LANGUAGES+= correct?
The action for target "fail-wrapper:" in mk/compiler.mk explicitly tells
us

  *** Please consider adding USE_LANGUAGES+=...

In chapter 23.2, the pkgsrc guide tells us more about USE_LANGUAGES but
I do not understand what it says.

Are we supposed to explicitly list a C compiler as necessary or can we
rely on the pkgsrc guide (and the comment in compiler.mk) that

  The default is "c"
 
?

ciao
     Klaus