Re: [PATCH v2] [gdb/testsuite, Tcl 9] Fix EILSEQ problems for UTF8 related tests

[Kevin Buettner <kevinb@redhat.com>]

On Tue, 26 May 2026 12:27:02 -0700
Kevin Buettner <kevinb@redhat.com> wrote:

> On Fedora 44 and Rawhide (Fedora 45), these tests...
> 
>   gdb.ada/non-ascii-utf-8.exp
>   gdb.base/utf8-identifiers.exp
>   gdb.rust/unicode.exp
> 
> ...all die due to these errors:
> 
>   Running ...gdb/testsuite/gdb.base/utf8-identifiers.exp ...
>   ERROR: tcl error sourcing
> .../gdb/testsuite/gdb.base/utf8-identifiers.exp. ERROR: tcl error code
> POSIX EILSEQ {invalid or incomplete multibyte or wide character} error
> writing "file6": invalid or incomplete multibyte or wide character ...
> 
> (I've shortened some of the pathnames for brevity.)
> 
> These Fedora systems are using Tcl 9 and also an updated version of
> dejagnu with this change applied:
> 
>   * Thu Apr 16 2026 Jakub Jelinek <jakub@redhat.com> - 1:1.6.3-17
>   - Apply full set of Tcl 9 compatibility fixes from upstream PR80674
> branch (#2448542)
> 
> That runtest change is responsible for the POSIX EILSEQ errors on
> machines with that change.  The change to runtest causing the change
> in behavior for GDB is the addition of these lines near the top of
> the runtest script:
> 
>   # Ensure that DejaGnu will be run in the POSIX locale
>   LC_ALL=C
>   export LC_ALL
> 
> Tcl 8 used a permissive encoding strategy: bytes that could not be
> represented in the current encoding were silently mangled or
> substituted.  Tcl 9 changed this default to a strict profile, which
> means that any attempt to write a character that cannot be expressed
> in the channel's encoding raises a POSIX EILSEQ error ("invalid or
> incomplete multibyte or wide character").
> 
> So, together, this Tcl 9 behavior combined with the dejagnu change
> to runtest causes the EILSEQ error for the tests mentioned earlier.
> 
> Fix it by using "fconfigure $handle -encoding utf-8 -profile replace"
> in proc spawn_capture_tty_name, and proc gdb_stdin_log_init.  Also,
> the open_logs wrapper has been changed to invoke fconfigure using only
> "-encoding utf-8".  Testing showed that "-profile replace" wasn't
> necessary there.
> 
> Tested on Fedora 28 (Tcl 8.6.8), Fedora 43 (Tcl 9.0.2 / 8.6.16; expect
> uses 8.6.16), Fedora 44 (Tcl 9.0.2 / 8.6.17; expect uses 9.0.2), and
> Rawhide / Fedora 45 (Tcl 9.0.3 / 8.6.18; expect uses 9.0.3).
> 
> With regard to the Bug noted below, I haven't been able to reproduce
> the failures in gdb.ada/lazy-string.exp, but I've been informed that
> this commit fixes it.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=34146
> Reviewed-By: Tom de Vries <tdevries@suse.de>

I've pushed this change.

Kevin