Re: [Bug-zile] Broken Hydra build

[Gary V. Vaughan]

Hi Reuben,

On 1 ต.ค. 2012, at 7:10, Reuben Thomas <address@hidden> wrote:
> See here: http://hydra.nixos.org/build/3116038

Very odd, since that very same tarball succeeds on other archs, so it must be 
something peculiar to the hydra x86 environment.

The error message says that '--output=doc/zile.1.in'  is 'not a file' at 
build-aux/missing line 51.

Inspecting build-aux/missing, the error message fits with the contents of the 
file, and yet all it's trying to do is handle being called as:

  build-aux/missing --run $(HELP2MAN) --output=doc/zile.1.in ...

where the relevant part of missing says:

...
case $1 in
  --run)
    shift
    "$@" && exit 0
    ...

So, the error can only come from HELP2MAN in Makefile being empty.

In configure.ac, HELP2MAN is set using:

   AX_WITH_PROG(HELP2MAN, help2man)

And the doc-comment at the top of ax_with_prog.m4 says that in this case, if 
help2man is not found then HELP2MAN is unchanged.

Conclusion, the failing hydra builds are on machines with no help2man 
executable in $PATH.

> The dates tally with this being broken by this commit:
> 
> commit f32a23baf20127ad02a1ae6634093414018459c3
> Author: Gary V. Vaughan <address@hidden>
> Date:   Fri Jul 13 22:51:15 2012 +0700
> 
>    configury: use missing to run help2man.
> 
>    * doc/Makefile.am (doc/zile.1.in): prepend build-aux/missing to the
>    help2man invocation so that it works with the distributed file when
>    the build host is missing a help2man binary.
> 
> Help?

Since we are using build-aux/missing to handle a lack of help2man already, 
rather than letting make try to run the unset $(HELP2MAN) directly, then all we 
need to do is set HELP2MAN unconditionally.  AX_WITH_PROG is still useful for 
allowing users to set weird locations for help2man using ./configure 
--with-help2man=/my/weird/path/help2man, so I think the best fix for this 
problem is to amend configure.ac:

  AX_WITH_PROG(HELP2MAN, help2man, help2man)

Which seems counter-intuitive, but hardcoding help2man directly removes the 
possibility for the user to override configure's guess at the location of 
help2man if necessary.

If you don't commit the fix yourself first, I'll do it after work today :)

Cheers,
-- 
Gary V. Vaughan (gary AT gnu DOT org)