As far as m4 goes, probably having
iff --git a/build/pkgs/gap/spkg-configure.m4
b/build/pkgs/gap/spkg-configure.m4
index 937fe400407..f754b29a455 100644
--- a/build/pkgs/gap/spkg-configure.m4
+++ b/build/pkgs/gap/spkg-configure.m4
@@ -13,14 +13,14 @@ SAGE_SPKG_CONFIGURE([gap], [
dnl so long as we don't initialize GAP with -r in Sage. But we
dnl don't want to include it in the hard-coded list.
GAPRUN="${GAP} -r -q --bare --nointeract -c"
- _cmd='Display(GAPInfo.KernelInfo.KERNEL_VERSION);'
+ _cmd='ColorPrompt(false);
Display(GAPInfo.KernelInfo.KERNEL_VERSION);'
GAP_VERSION=$( ${GAPRUN} "${_cmd}" 2>/dev/null )
AX_COMPARE_VERSION(["${GAP_VERSION}"], [ge], [GAP_MINVER], [dnl
AC_MSG_RESULT([yes])
AX_COMPARE_VERSION(["${GAP_VERSION}"], [lt], [GAP_LTVER], [dnl
AC_MSG_RESULT([yes])
AC_MSG_CHECKING([for gap root paths])
- _cmd='Display(JoinStringsWithSeparator(GAPInfo.RootPaths,";"));'
+ _cmd='ColorPrompt(false);
Display(JoinStringsWithSeparator(GAPInfo.RootPaths,";"));'
SYS_GAP_ROOT_PATHS=$( ${GAPRUN} "${_cmd}" 2>/dev/null )
AC_MSG_RESULT([$SYS_GAP_ROOT_PATHS])
AS_IF([test -n "${SYS_GAP_ROOT_PATHS}"], [
would avoid the trouble you have. (after the usual ./bootstrap etc etc)
On Tue, Mar 3, 2026 at 10:19 AM Marc Culler <[email protected]> wrote:
> I managed to track this down.
>
> First, I found this in sage/sage-distro/meson-logs/meson-log.txt:
>
>
>
>
>
>
>
> *Running command: /var/tmp/sage-10.9/local/bin/gap -r -q --bare
> --nointeract
> -c 'Display(JoinStringsWithSeparator(GAPInfo.RootPaths,";"));'--- stdout
> ---ESC[?1034h/var/tmp/sage-10.9/local/lib/gap/;/var/tmp/sage-10.9/local/share/gap/---
> stderr ---*
> So, meson is running sage's gap executable to find its root paths. But
> it is getting the "set 8 bit meta" escape sequence at the beginning of the
> gap output.
>
> If I run that command in the shell I do not get the escape sequence:
>
> sage/local/bin/gap -r -q --bare --nointeract -c
> 'Display(JoinStringsWithSeparator(GAPInfo.RootPaths,";"));' | xxd
> 00000000: 2f76 6172 2f74 6d70 2f73 6167 652d 3130 /var/tmp/sage-10
> 00000010: 2e39 2f6c 6f63 616c 2f6c 6962 2f67 6170 .9/local/lib/gap
> 00000020: 2f3b 2f76 6172 2f74 6d70 2f73 6167 652d /;/var/tmp/sage-
> 00000030: 3130 2e39 2f6c 6f63 616c 2f73 6861 7265 10.9/local/share
> 00000040: 2f67 6170 2f0a /gap/.
>
> However, clearly there are times when the escape sequence does get added.
>
> The culprit turns out to be readline-6.2, which is what my docker image
> happens to be using. Gemini was able to find some information about this:
>
> * Version 6.3 Fix*: In earlier versions (notably 6.0 through 6.2),
> rl_initialize() would output the "Meta mode ON" sequence to stdout
> even if the output was not a terminal, causing issues like
> corrupted script output and erroneous characters in program pipes.
>
> This problem did not occur with 10.8. The difference is probably that the
> rl_initialize was being called at some earlier stage of the build process,
> so the escape sequence was being emitted somewhere else, not in the step
> where the GAP root paths are constructed.
>
> Moral: It is always something.
>
> - Marc
>
>
>
>
> On Tuesday, March 3, 2026 at 8:25:29 AM UTC-6 Marc Culler wrote:
>
>> I can tell you something about where it came from.
>>
>> When I look at sage/local/lib/python3.14/site-packages/sage/config.py I
>> see:
>>
>>
>>
>>
>> *# The semicolon-separated list of GAP root paths. This is the list of#
>> locations that are searched for GAP packages. This is passed directly# to
>> GAP via the -l flag.GAP_ROOT_PATHS =
>> "ESC[?1034h/var/tmp/sage-10.9/local/lib/gap/;/var/tmp/sage-10.9/local/share/gap/".replace("${prefix}",
>> SAGE_LOCAL)*
>>
>> The file config.py is generated from sage/src/sage/config.py.in, which
>> contains:
>>
>>
>>
>>
>> *# The semicolon-separated list of GAP root paths. This is the list of#
>> locations that are searched for GAP packages. This is passed directly# to
>> GAP via the -l flag.GAP_ROOT_PATHS =
>> "@GAP_ROOT_PATHS@".replace("${prefix}", SAGE_LOCAL)*
>>
>> So it would seem that some m4 file is inserting the "enable 8 bit meta"
>> escape sequence into @GAP_ROOT_PATHS@ for my enjoyment and entertainment.
>>
>> Also, when I remove that escape sequence from config.py, guess what?
>>
>> sage: gap.FreeGroup(3)
>> Group( [ f1, f2, f3 ] )
>>
>> - Marc
>>
>>
>>
>> On Monday, March 2, 2026 at 11:35:18 PM UTC-6 [email protected] wrote:
>>
>>> "\033[?1034h/var/tmp/sage-10.9/local/lib/gap/" is certainly looking bad,
>>> and probably is the root of the problem.
>>>
>>> No idea where it came from.
>>>
>>>
>>>
>>> On Mon, Mar 2, 2026 at 9:52 PM Marc Culler <[email protected]> wrote:
>>>
>>>> I deleted .sage/gap and tried again. No change.
>>>>
>>>> I also tried
>>>> sage: libgap.eval('F:= FreeGroup(3)')
>>>> That produces the same GAPError, but there was some other stuff printed
>>>> before the traceback which might provide a clue:
>>>>
>>>> #I gapdoc package is not available. Check that the name is correct
>>>> #I and it is present in one of the GAP root directories (see
>>>> '??RootPaths')
>>>> #I GAP: needed package gapdoc cannot be loaded
>>>> Error, failed to load needed package `gapdoc' (version >= 1.2)
>>>> Syntax warning: Unbound global variable in
>>>> /var/tmp/sage-10.9/local/share/gap/l\
>>>> ib/init.g:728
>>>> ColorPrompt( UserPreference( "UseColorPrompt" ) );
>>>> ^^^^^^^^^^^
>>>> Error, SetGasmanMessageStatus: function is not yet defined
>>>> Error, Variable: 'L1_IMMUTABLE_ERROR' must have a value
>>>> Error, Variable: 'ColorPrompt' must have a value
>>>>
>>>> I did find some other suspicious stuff:
>>>>
>>>> sage: libgap.eval('GAPInfo.RootPaths')
>>>> [ "/home/culler/.gap/", "\033[?1034h/var/tmp/sage-10.9/local/lib/gap/",
>>>> "/var/tmp/sage-10.9/local/share/gap/" ]
>>>>
>>>> The last path contains an empty pkg directory. The real pkg directory
>>>> is in $SAGE_ROOT/local/lib/gap. But I doubt that the second path would
>>>> work correctly when it has all of those ANSI escape sequences in front of
>>>> it. Adding a symlink /var/tmp/sage-10.9/local/share/gap/pkg ->
>>>> ../../lib/gap/pkg did not help. But maybe putting ANSI escape sequences in
>>>> a root path makes GAP crash.
>>>>
>>>> - Marc
>>>>
>>>>
>>>> - Marc
>>>>
>>>> On Mon, Mar 2, 2026 at 9:13 PM Dima Pasechnik <[email protected]> wrote:
>>>>
>>>>> The usual suspects for strange GAP errors are stale GAP workspaces (or
>>>>> related to them errors). Make sure you don't have any (typically in
>>>>> ~/.sage/, although your setup might have a different location of .sage/)
>>>>>
>>>>>
>>>>>
>>>>> On March 2, 2026 4:37:34 PM CST, Marc Culler <[email protected]>
>>>>> wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> On Monday, March 2, 2026 at 3:32:23 PM UTC-6 [email protected] wrote:
>>>>>>
>>>>>>
>>>>>> That's a problem with the pexpect GAP. Does
>>>>>>
>>>>>> sage: libgap.FreeGroup(3)
>>>>>>
>>>>>> work?
>>>>>>
>>>>>>
>>>>>> No. I don't get a RuntimeError (which I think is produced by
>>>>>> pexpect) but I get:
>>>>>>
>>>>>> GAPError: Error, FreeGroup: function is not yet defined
>>>>>>
>>>>>> Does
>>>>>>
>>>>>> ./sage -t src/sage/features/gap.py
>>>>>>
>>>>>> pass?
>>>>>>
>>>>>>
>>>>>> Yes. I get:
>>>>>>
>>>>>> Doctesting 1 file.
>>>>>> sage/src/bin/sage -t --warn-long 5.0
>>>>>> --random-seed=206062923921806203470542245493080431476
>>>>>> sage/src/sage/features/gap.py
>>>>>> [5 tests, 0.01s wall]
>>>>>> ----------------------------------------------------------------------
>>>>>> All tests passed!
>>>>>> ----------------------------------------------------------------------
>>>>>> Total time for all tests: 0.2 seconds
>>>>>> cpu time: 0.0 seconds
>>>>>> cumulative wall time: 0.0 seconds
>>>>>> Features detected for doctesting:
>>>>>>
>>>>>> - Marc
>>>>>>
>>>>>> --
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>>>>> .
>>>>>
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