Re: bug in texi2dvi, on Windows/Msys2 it cannot find tex

[Tomas Kalibera]

On 4/8/22 14:56, Gavin Smith wrote:
> On Wed, Apr 06, 2022 at 05:24:01PM +0300, Eli Zaretskii wrote:
> > > Date: Wed, 6 Apr 2022 14:39:30 +0200
> > > From: Tomas Kalibera <tomas.kalibera@gmail.com>
> > >
> > > texi2dvi on Msys2 doesn't find tex, because it incorrectly detects ";"
> > > as path separator (it is ":").
> > >
> > > The problem is in the following code. With Msys2, OSTYPE is "msys", but
> > > MSYSTEM is upper-case "MSYS" and uname needs it that way:
> > >
> > > # In the case of Msys, uname returns a value derived from MSYSTEM, as
> > > # MSYSTEM is user configurable, it is not so safe to use it to detect
> > > # Msys. It is safer to use OSTYPE, this is why we set MSYSTEM to
> > > # $OSTYPE before calling uname
> > > if test -n "$COMSPEC$ComSpec" \
> > >      && MSYSTEM=$OSTYPE uname | $EGREP -iv 'cygwin|msys' >/dev/null; then
> > >     path_sep=";"
> > > else
> > >     path_sep=":"
> > > fi
> > >
> > > I've reported this with more detail for Msys2
> > > (https://github.com/msys2/MSYS2-packages/issues/2901) but perhaps it is
> > > worth fixing upstream as the code was meant to support MSYS.
> > MSYS is already supported; it is MSYS2 that deviated from the original
> > MSYS behavior, and now support for MSYS2 needs to be _added_.
> >
> > IOW, whatever is done here to ensure support for MSYS2, please do NOT
> > remove the current test, which does work with the original MSYS.
> > Please tweak the test so that it accepts both flavors.
> What happens if we don't set MSYSTEM at all?
>
> diff --git a/util/texi2dvi b/util/texi2dvi
> index 1f42b41907..c506bbad37 100755
> --- a/util/texi2dvi
> +++ b/util/texi2dvi
> @@ -85,7 +85,7 @@ IFS="$space$tab$newline"
>   # Msys. It is safer to use OSTYPE, this is why we set MSYSTEM to
>   # $OSTYPE before calling uname
>   if test -n "$COMSPEC$ComSpec" \
> -   && MSYSTEM=$OSTYPE uname | $EGREP -iv 'cygwin|msys' >/dev/null; then
> +   && uname | $EGREP -iv 'cygwin|msys' >/dev/null; then
>     path_sep=";"
>   else
>     path_sep=":"

It works with Msys2 and cygwin for me, but breaks with MSYSTEM, where

$ uname
MINGW32_NT-6.2

$ MSYSTEM=$OSTYPE uname
msys_NT-6.2

$ uname -a
MINGW32_NT-6.2 DESKTOP-G858KME 1.0.19(0.48/3/2) 2016-07-13 17:45 i686 Msys

Tomas

> This was added on 2015-09-23 in what is now git commit 02cc28bb352be.
>
> Link to discussion at that time:
>
> https://lists.gnu.org/archive/html/bug-texinfo/2015-09/msg00078.html
>
> I didn't see an explanation there to state that setting MSYSTEM was
> actually necessary, just the comment that it is "safer", which it transpires
> it is not.
>
> I don't actually understand what the thinking was behind setting MSYSTEM
> in the first place or what problem this was meant to solve.
>
> Methinks if MSYSTEM needs to be set correctly for uname to have the correct
> output, then the user will already have this set in their environment.
> Otherwise it is a broken system that we don't need to worry about supporting.
> Am I wrong?