Re: fix: propagate M4 env variable to flex subprocess

Hi,

On Tue, 13 May 2025 at 18:54, Andres Freund <andres(at)anarazel(dot)de> wrote:
>
> Hi,
>
> On 2025-05-12 23:14:59 -0400, J. Javier Maestro wrote:
> > The pgflex wrapper runs flex with an explicit environment, so it doesn't
> > inherit environment variables from the parent process. However, flex can
> > use the M4 env variable and/or the PATH (via execvp) to find the m4 macro
> > processor.
>
> > Thus, since flex honors the M4 env variable, it should be propagated to the
> > subprocess environment if it's set in the parent environment. This patch
> > fixes it.
>
> I think it probably was not intentional to fully specify the environment,
> rather than just *adding* FLEX_TMP_DIR to the caller's environment. Bilal, I
> think you wrote this originally, do you recall?

I found the original pull request [1] but it does not include the
'FLEX_TMP_DIR' part. I tried to search where the 'FLEX_TMP_DIR' part
is added [2], it seems that this part is added while rebasing so there
is no specific commit.

[1] https://github.com/anarazel/postgres/pull/51
[2] https://github.com/anarazel/postgres/commit/cd817afd4ab006b90307a940d96b5116d649165c

--
Regards,
Nazir Bilal Yavuz
Microsoft