Re: [PATCH] Documentation/Makefile: remove cmd-list.made before redirecting to it.

[Junio C Hamano <gitster@pobox.com>]

David Kastrup <dak@gnu.org> writes:

> If cmd-list.made has been created by a previous run as root, output
> redirection to it will fail.  So remove it before regeneration.
>
> Signed-off-by: David Kastrup <dak@gnu.org>
> ---
>  Documentation/Makefile |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/Makefile b/Documentation/Makefile
> index 97ee067..120e7c0 100644
> --- a/Documentation/Makefile
> +++ b/Documentation/Makefile
> @@ -120,6 +120,7 @@ $(cmds_txt): cmd-list.made
>  
>  cmd-list.made: cmd-list.perl $(MAN1_TXT)
>  	perl ./cmd-list.perl
> +	$(RM) $@
>  	date >$@
>  
>  git.7 git.html: git.txt core-intro.txt

Although I understand that it would be a problem if you built as
root earlier, which would have left files unmodifyable by you, I
think this is getting out of hand.  The cmd-list.perl script
itself, for example, does "creat in $out+, if the contents have
changed from the last round then rename $out+ to $out" sequence
in order to avoid unnecessary rebuild of files that depend on
the generated command list.  If it is interrupted in the middle
while running as root, and then you try to do another build, I
suspect "creat in $out+" part would fail.

Maybe you can simply recover from such an error with a "make
clean"?

Also I'd prefer $(RM) before actually running the command to
generate the list, but that is just the matter of taste.