Re: [gentoo-portage-dev] [PATCH] eapply: Output verbosely only if patch fails to apply with -F0

[Zac Medico]

On 11/27/19 10:54 AM, Michał Górny wrote:
> 12d0c48ad disabled silent output for eapply, in order to obtain fuzz
> factors in build logs.  However, this also causes eapply to report all
> patched files which can make logs unreadable when there are no fuzz
> factors to be reported.  Instead, use verbose output only when applying
> the patch with -F0 fails.
>
> To achieve that, attempt to apply each patch with -F0 --dry-run first.
> If this succeeds, just silently apply the patch for real.  If it
> doesn't, output an explicit eqawarn that the patch does not apply
> cleanly and retry with the default fuzz factor and verbose output.
> Non-silenced output applies both to successful application with fuzz
> and to failure.
>
> Signed-off-by: Michał Górny <mgorny@g.o>
> ---
>  bin/phase-helpers.sh | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/bin/phase-helpers.sh b/bin/phase-helpers.sh
> index 60f8d3243..6f9b52678 100644
> --- a/bin/phase-helpers.sh
> +++ b/bin/phase-helpers.sh
> @@ -995,8 +995,20 @@ if ___eapi_has_eapply; then
>  			# -f to avoid interactivity
>  			# -g0 to guarantee no VCS interaction
>  			# --no-backup-if-mismatch not to pollute the sources
> -			${patch_cmd} -p1 -f -g0 --no-backup-if-mismatch \
> -				"${patch_options[@]}" < "${f}"
> +			local all_opts=(
> +				-p1 -f -g0 --no-backup-if-mismatch
> +				"${patch_options[@]}"
> +			)
> +			# try applying with -F0 first, output a verbose warning
> +			# if fuzz factor is necessary
> +			if ${patch_cmd} "${all_opts[@]}" --dry-run -s -F0 \
> +					< "${f}" &>/dev/null; then
> +				all_opts+=( -s -F0 )
> +			else
> +				eqawarn "    patch failed to apply without a fuzz factor, please rebase"

The earlier ebegin call only outputs the basename, so there could be
some confusion about the origin of the patch. This function is also
called by eapply_user, it's possible that people could get confused and
report bugs about fuzz in their local patches. Other than that it looks
good.

> +			fi
> +
> +			${patch_cmd} "${all_opts[@]}" < "${f}"
>  			failed=${?}
>  			if ! eend "${failed}"; then
>  				__helpers_die "patch -p1 ${patch_options[*]} failed with ${f}"
>
-- 
Thanks,
Zac