Re: [PATCH] build-sys: fix git version from -version

[Eric Blake]

On 9/29/20 8:42 AM, marcandre.lureau@redhat.com wrote:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> Typo introduced with the script.
>
> Fixes: 2c273f32d3 ("meson: generate qemu-version.h")
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>   scripts/qemu-version.sh | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/scripts/qemu-version.sh b/scripts/qemu-version.sh
> index 03128c56a2..430a7fc581 100755
> --- a/scripts/qemu-version.sh
> +++ b/scripts/qemu-version.sh
> @@ -9,7 +9,7 @@ version="$3"
>   if [ -z "$pkgversion" ]; then
>       cd "$dir"
>       if [ -e .git ]; then
> -        pkgversion=$(git describe --match 'v*' --dirty | echo "")

This always produces pkgversion="" (the git describe output is ignored 
when it is piped to echo).

> +        pkgversion=$(git describe --match 'v*' --dirty || echo "")

But this just looks weird. $(echo "") is the same as "".  The REAL goal 
here appears to be that you want 'set -e' to not die if git describe has 
a non-zero exit status.  But that's shorter to write as:

pkgversion=$(git describe --match 'v*' --dirty || :)

or even

pkgversion=$(git describe --match 'v*' --dirty) || :


--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org