libterm-filter-perl: FTBFS randomly (failing tests)

[Bryce Harrington]

This package has a history of intermittent test failures, that resolve once retried enough times:

https://autopkgtest.ubuntu.com/packages/libt/libterm-filter-perl/lunar/amd64

Example failure:
https://autopkgtest.ubuntu.com/results/autopkgtest-lunar/lunar/amd64/libt/libterm-filter-perl/20230125_010834_040c2@/log.gz

autopkgtest [00:44:15]: test autodep8-perl-build-deps: [-----------------------
t/00-compile.t ............
1..1
ok 1 - Debian::pkgperl::Foobar loaded ok
ok
t/basic.t .................
ok 1
ok 2
ok 3
1..3
ok
t/callbacks.t .............
ok 1 - setup callback got a Term::Filter::Callback object
not ok 2 - munge_input and munge_output got the right arguments

# Failed test 'munge_input and munge_output got the right arguments'
# at t/callbacks.t line 70.
# 'MUNGE_INPUT: Term::Filter::Callback=HASH(0x55ed8fc7a960) (Term::Filter::Callback): fOo
#
# MUNGE_OUTPUT: Term::Filter::Callback=HASH(0x55ed8fc7a960) (Term::Filter::Callback): FOO
#
# foo
# MUNGE_OUTPUT: Term::Filter::Callback=HASH(0x55ed8fc7a960) (Term::Filter::Callback): FOO
# fooMUNGE_OUTPUT: Term::Filter::Callback=HASH(0x55ed8fc7a960) (Term::Filter::Callback):
#
#
# '
# doesn't match '(?^sx:
# ^
# MUNGE_INPUT: \s Term\:\:Filter\:\:Callback\=HASH\(0x55ed8fc7a960\) \s \(Term::Filter::Callback\): \s fOo\n
# \n
# (?:
# MUNGE_OUTPUT: \s Term\:\:Filter\:\:Callback\=HASH\(0x55ed8fc7a960\) \s \(Term::Filter::Callback\): \s FOO(?^:\x0d\x0a)
# \n
# foo(?^:\x0d\x0a)
# MUNGE_OUTPUT: \s Term\:\:Filter\:\:Callback\=HASH\(0x55ed8fc7a960\) \s \(Term::Filter::Callback\): \s FOO(?^:\x0d\x0a)
# \n
# foo(?^:\x0d\x0a)
# |
# MUNGE_OUTPUT: \s Term\:\:Filter\:\:Callback\=HASH\(0x55ed8fc7a960\) \s \(Term::Filter::Callback\): \s FOO(?^:\x0d\x0a) FOO(?^:\x0d\x0a)
# \n
# foo(?^:\x0d\x0a)
# foo(?^:\x0d\x0a)
# )
# $
# )'

Debian also sees randomly failing tests, as per this bug:
  - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=843052

There's some analysis on that bug but no solution or reliable workarounds yet.