fox for #302. refuse to build if troff and nroff are not around

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@2188 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/configure.ac b/configure.ac
index 10603bd..0a68ceb 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -904,8 +904,16 @@ fi
 AC_SUBST(COMP_PYTHON)
 
 dnl Check for nroff
-AC_PATH_PROGS(NROFF, gnroff nroff)
-AC_PATH_PROGS(TROFF, groff troff)
+AC_ARG_VAR(NROFF, [path to the local nroff version])
+AC_PATH_PROGS(NROFF, [gnroff nroff])
+if test x$NROFF = x; then
+  AC_MSG_ERROR([I need a copy of *nroff to format the documentation])
+fi
+AC_ARG_VAR(TROFF, [path to the local troff version])
+AC_PATH_PROGS(TROFF, [groff troff])
+if test x$TROFF = x; then
+  AC_MSG_ERROR([I need a copy of *troff to format the documentation])
+fi
 
 AC_ARG_VAR(RRDDOCDIR, [[DATADIR/doc/PACKAGE-VERSION] Documentation directory])
 if test -z "$RRDDOCDIR"; then