[njs] Added explanation for why njs CLI cannot be built.

[Dmitry Volyntsev]

details:   https://hg.nginx.org/njs/rev/44e41970a160
branches:  
changeset: 1223:44e41970a160
user:      Dmitry Volyntsev <xeioex at nginx.com>
date:      Tue Nov 05 20:49:56 2019 +0300
description:
Added explanation for why njs CLI cannot be built.

diffstat:

 auto/make |  15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diffs (32 lines):

diff -r bb0bac71da3f -r 44e41970a160 auto/make
--- a/auto/make	Tue Nov 05 20:49:56 2019 +0300
+++ b/auto/make	Tue Nov 05 20:49:56 2019 +0300
@@ -91,6 +91,8 @@ done
 
 # njs cli.
 
+if [ $NJS_HAVE_READLINE = YES ]; then
+
 cat << END >> $NJS_MAKEFILE
 
 $NJS_BUILD_DIR/njs: \\
@@ -104,6 +106,19 @@ cat << END >> $NJS_MAKEFILE
 
 END
 
+else
+
+cat << END >> $NJS_MAKEFILE
+
+$NJS_BUILD_DIR/njs:
+	@echo
+	@echo " error: to make njs CLI \"readline\" library is required."
+	@echo
+	@exit 1
+
+END
+
+fi
 
 # lib tests.