[Buildroot] [PATCH] fbgrab: explicitly build fbgrab target to workaround gzip issue

[Peter Korsgaard <peter@korsgaard.com>]

Fixes #9871

gzip reads default command line options from the environment variable GZIP.
The fbgrab Makefile internally also uses a GZIP make variable to know what
command to use to compress the manpage. Unfortunaly make will export the
value of this make variable to the environment if GZIP is already present in
the enviroment, confusing gzip (as 'gzip' isn't a valid command line argument).

This can either be triggered by users having GZIP set in their environment
(E.G.  for custom options), or by enabling BR2_REPRODUCIBLE, where we use
this feature to force the -n option (to not store name/timestamp) to gzip.

We don't really need to compress the manpage as it isn't installed anyway,
so work around the issue by only building the fbgrab application.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
 package/fbgrab/fbgrab.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/fbgrab/fbgrab.mk b/package/fbgrab/fbgrab.mk
index 15e0a95c9..d81a5ee2a 100644
--- a/package/fbgrab/fbgrab.mk
+++ b/package/fbgrab/fbgrab.mk
@@ -11,7 +11,7 @@ FBGRAB_LICENSE = GPL-2.0
 FBGRAB_LICENSE_FILES = COPYING
 
 define FBGRAB_BUILD_CMDS
-	$(TARGET_CONFIGURE_OPTS) $(MAKE) -C $(@D)
+	$(TARGET_CONFIGURE_OPTS) $(MAKE) -C $(@D) fbgrab
 endef
 
 define FBGRAB_INSTALL_TARGET_CMDS
-- 
2.11.0