[ovs-dev] [PATCH ovn] configure: Save OVSDIR as an absolute path.

[Mark Michelson]

On 3/22/21 2:02 PM, Mark Michelson wrote:
> Lately, `make check` runs have been failing. When "--with-ovs-source"
> is not specified at configure time, the configure script automatically
> sets the location to "$srcdir/ovs". This location is passed along the
> chain and eventually added to AUTOTEST_PATH when running the tests.
> 
> $srcdir is a relative path name, which is fine when building the code.
> This falls apart, though, when tests are run. Tests are not run from
> the build directory, but instead from the tests/ directory. Therefore,
> the relative path to ovs/ is different. This causes most tests to fail
> since files are not in the expected location.
> 
> The fix is to set OVSDIR to an absolute path instead. Autoconf documents
> an $abs_srcdir variable, but this is not set until after configure
> checks are run. It is meant to be used by Makefiles. Therefore, we use
> the trick of cd-ing to the directory and calling pwd to expand it to the
> absolute path.
> 
> Signed-off-by: Mark Michelson <mmichels at redhat.com>

I didn't mention this above, but there is also an $ac_abs_confdir 
variable that expands to the absolute path of the configure script. I 
tested and this works as well, but general advice online is not to use 
this. It's a variable internal to autoconf, it's not documented, and it 
has the potential to be removed without notice in some future autoconf 
version.

> ---
>   acinclude.m4 | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/acinclude.m4 b/acinclude.m4
> index 3f8db03cf..2c607ea8e 100644
> --- a/acinclude.m4
> +++ b/acinclude.m4
> @@ -381,7 +381,7 @@ AC_DEFUN([OVN_CHECK_OVS], [
>         AC_ERROR([$OVSDIR is not an OVS source directory])
>       fi
>     else
> -    OVSDIR=$srcdir/ovs
> +    OVSDIR=$(cd $srcdir/ovs; pwd)
>     fi
>   
>     AC_MSG_RESULT([$OVSDIR])
>