X-Git-Url: http://git.tuebingen.mpg.de/?p=lopsub.git;a=blobdiff_plain;f=Makefile;h=c0057a38b89119897044caa0a1eaa705877989ca;hp=200a7c0d411b5e8cc90c354576d36759a9c63028;hb=7623e601612eb36cf86511b40fef3f5a20e8b834;hpb=d6f28609ba3b250079ac0c55422dafdabb6c0c71

diff --git a/Makefile b/Makefile
index 200a7c0..c0057a3 100644
--- a/Makefile
+++ b/Makefile
@@ -21,6 +21,15 @@ INSTALL := install
 GZIP := gzip -fn9
 ZCAT := zcat
 
+dummy != $(M4) /dev/null || printf 'failed'
+ifeq ($(dummy), failed)
+$(error m4 is required to build this package)
+endif
+dummy != printf '%%%%\n' | $(LEX) -o /dev/null || printf 'failed'
+ifeq ($(dummy), failed)
+$(error (f)lex is required to build this package)
+endif
+
 DATE_FMT := +%B %Y
 # To get a reproducible build, we use $(SOURCE_DATE_EPOCH) instead of the
 # current time if this variable is set.