Cannot build GRUB2 boot loader image in Clear Linux

[gvancuts]

Describe the bug
It is not possible to build the GRUB2 boot loader image as described in the here on a Clear Linux (ver. 28230) system.

To Reproduce
Steps to reproduce the behavior:

1. Make sure you have this patch (still being reviewed) in your tree
2. Run: $ ./boards/x86/common/scripts/build_grub.sh x86_64
3. This results in the following error (snipped):

    -e "/OUTPUT_TERMINAL_LIST_MARKER *( *\"/{s/.*( *\"\([^\"]*\)\".*/o\1: $b/;p;}" $pp; \
done) | sort -u > terminal.lst
In file included from ../include/grub/dl.h:29,
                 from loader/i386/bsd.c:26:
loader/i386/bsd.c: In function ‘grub_cmd_openbsd’:
../include/grub/misc.h:71:10: error: ‘ptr’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
   return grub_memmove (dest, src, n);
          ^~~~~~~~~~~~~~~~~~~~~~~~~~~
loader/i386/bsd.c:264:9: note: ‘ptr’ was declared here
   void *ptr;
         ^~~
In file included from ../include/grub/dl.h:29,

Expected behavior
grub_x86_64.efi is correctly generated.

Impact
Clear Linux cannot be used as the development machine. The other environment that I have tested was Fedora 29 (with this patch), that works correctly.

Environment (please complete the following information):

• OS: Clear Linux 28230
• Toolchain: native tools

[andrewboie]

Your referenced patch got merged, may we close this?

[gvancuts]

Your referenced patch got merged, may we close this?

My bad, I forgot to add the Fixes: tag... sorry about that.

[gvancuts]

This seems to have come back (sigh), I cannot identify what changed in the meantime and the failure has been reported by different sources. I've tried the latest Clear Linux version (as of today: 28510) and the problem is reproducible in that environment too... reopening.

[gvancuts]

One of the CFLAGS setting in Clear Linux is causing this, if you unset it before calling the script, it will successfully generate the grub_x86_64.efi file.

A (pretty unrefined) patch would be to unset this from the script directly, i.e.:

index 11b2067fe5..9b5b0801e4 100755
--- a/boards/x86/common/scripts/build_grub.sh
+++ b/boards/x86/common/scripts/build_grub.sh
@@ -4,6 +4,7 @@
 # https://github.com/otcshare/contiki-x86
 
 set -e
+unset CFLAGS
 
 JOBS=5
 SCRIPT_DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )

Note: this only unsets CFLAGS in the context of the script. Clear Linux environment still has it after you run the script.