From 71ed858508e350aa304278ece867f54bd0814921 Mon Sep 17 00:00:00 2001
From: "David E. Wheeler" <david@justatheory.com>
Date: Fri, 29 Dec 2023 19:00:22 -0500
Subject: [PATCH] Use locale pragma instead of POSIX::set_locale()

The Pragma is more likely to do the right thing, as confirmed by new
tests, which fail when using `setlocale` and now succeed with `use
locale`. The tests, in `xt/locale`, include compiled locale dictionaries
(`*.mo` files) with a single message for the tested languages. This is
in contrast to the released locale dictionaries, which are generated at
release time but not stored in the repository.

Update the `os.yml` and `perl.yml` workflows, which run all tests
including the new locale tests, to install the required locales on Linux
and to set the full `runs-on:` image name in the matrix (in response to
shogo82148/actions-setup-perl#1699).

Also remove the installation of an older version of Locale::TextDomain
from those workflows, since gflohr/libintl-perl#7 has been fixed and
released.

While at it, upgrade to `actions/checkout@v4` in all workflows and use
`runner.os` instead of `matrix.os` in conditionals.
---
 .github/workflows/cockroach.yml               |   2 +-
 .github/workflows/coverage.yml                |   2 +-
 .github/workflows/exasol.yml                  |   2 +-
 .github/workflows/firebird.yml                |   2 +-
 .github/workflows/mysql.yml                   |   2 +-
 .github/workflows/oracle.yml                  |   2 +-
 .github/workflows/os.yml                      |  18 +++----
 .github/workflows/perl.yml                    |  14 +++---
 .github/workflows/pg.yml                      |   2 +-
 .github/workflows/release.yml                 |   2 +-
 .github/workflows/snowflake.yml               |   2 +-
 .github/workflows/sqlite.yml                  |   2 +-
 .github/workflows/vertica.yml                 |   2 +-
 .github/workflows/yugabyte.yml                |   2 +-
 .gitignore                                    |   3 +-
 Changes                                       |   3 ++
 bin/sqitch                                    |  11 +----
 t/sqitch                                      |  10 +---
 .../de_DE/LC_MESSAGES/App-Sqitch.mo           | Bin 0 -> 209 bytes
 .../fr_FR/LC_MESSAGES/App-Sqitch.mo           | Bin 0 -> 212 bytes
 .../it_IT/LC_MESSAGES/App-Sqitch.mo           | Bin 0 -> 207 bytes
 xt/locale/README.md                           |  45 ++++++++++++++++++
 xt/locale/po/de_DE.po                         |   6 +++
 xt/locale/po/fr_FR.po                         |   6 +++
 xt/locale/po/it_IT.po                         |   6 +++
 xt/locale/test-cli.t                          |  36 ++++++++++++++
 26 files changed, 136 insertions(+), 46 deletions(-)
 create mode 100644 xt/locale/LocaleData/de_DE/LC_MESSAGES/App-Sqitch.mo
 create mode 100644 xt/locale/LocaleData/fr_FR/LC_MESSAGES/App-Sqitch.mo
 create mode 100644 xt/locale/LocaleData/it_IT/LC_MESSAGES/App-Sqitch.mo
 create mode 100644 xt/locale/README.md
 create mode 100644 xt/locale/po/de_DE.po
 create mode 100644 xt/locale/po/fr_FR.po
 create mode 100644 xt/locale/po/it_IT.po
 create mode 100644 xt/locale/test-cli.t

diff --git a/.github/workflows/cockroach.yml b/.github/workflows/cockroach.yml
index a6087cac3..6466785b3 100644
--- a/.github/workflows/cockroach.yml
+++ b/.github/workflows/cockroach.yml
@@ -18,7 +18,7 @@ jobs:
     steps:
       - name: Start CockroachDB
         run: docker run -d -p 26257:26257 cockroachdb/cockroach:latest-v${{ matrix.version }} start-single-node --insecure
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index b433912a1..500bc8eb4 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -49,7 +49,7 @@ jobs:
         run: rm -rf /opt/hostedtoolcache
       - name: Start CockroachDB
         run: docker run -d -p 26257:26257 cockroachdb/cockroach:latest start-single-node --insecure
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
diff --git a/.github/workflows/exasol.yml b/.github/workflows/exasol.yml
index d10db9d22..1f33fd39a 100644
--- a/.github/workflows/exasol.yml
+++ b/.github/workflows/exasol.yml
@@ -20,7 +20,7 @@ jobs:
         ports: [ 8563 ]
         options: --privileged
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Clients
         run: .github/ubuntu/exasol.sh
       - name: Setup Perl
diff --git a/.github/workflows/firebird.yml b/.github/workflows/firebird.yml
index 36a5541a4..de7c120ed 100644
--- a/.github/workflows/firebird.yml
+++ b/.github/workflows/firebird.yml
@@ -29,7 +29,7 @@ jobs:
           ISC_PASSWORD: nix
           FIREBIRD_DATABASE: sqitchtest.db
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Clients
         run: .github/ubuntu/firebird.sh
       - name: Setup Perl
diff --git a/.github/workflows/mysql.yml b/.github/workflows/mysql.yml
index 14cb78ac6..03a7beecf 100644
--- a/.github/workflows/mysql.yml
+++ b/.github/workflows/mysql.yml
@@ -39,7 +39,7 @@ jobs:
         ports: [ 3306 ]
         options: --health-cmd="healthcheck.sh --innodb_initialized || mysqladmin ping --protocol=tcp" --health-interval=5s --health-timeout=2s --health-retries=3
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Clients
         run: .github/ubuntu/mysql.sh
       - name: Setup Perl
diff --git a/.github/workflows/oracle.yml b/.github/workflows/oracle.yml
index 186501eb3..ea8487ace 100644
--- a/.github/workflows/oracle.yml
+++ b/.github/workflows/oracle.yml
@@ -40,7 +40,7 @@ jobs:
           --health-timeout 10s
           --health-retries 10
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Clients
         run: .github/ubuntu/oracle.sh
       - name: Setup Perl
diff --git a/.github/workflows/os.yml b/.github/workflows/os.yml
index 6293bb68e..5ecf1d417 100644
--- a/.github/workflows/os.yml
+++ b/.github/workflows/os.yml
@@ -12,27 +12,29 @@ jobs:
     strategy:
       matrix:
         include:
-          - { icon: 🐧, os: ubuntu,  name: Linux }
-          - { icon: 🍎, os: macos,   name: macOS }
-          - { icon: 🪟, os: windows, name: Windows }
+          - { icon: 🐧, on: ubuntu-latest,  name: Linux }
+          - { icon: 🍎, on: macos-latest,   name: macOS }
+          - { icon: 🪟, on: windows-latest, name: Windows }
     name: ${{ matrix.icon }} ${{ matrix.name }}
-    runs-on: ${{ matrix.os }}-latest
+    runs-on: ${{ matrix.on }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
         with: { perl-version: latest }
       - run: perl -V
+      - if: runner.os == 'Linux'
+        name: Install Apt Packages
+        run: sudo apt-get install -qq aspell-en language-pack-fr language-pack-en language-pack-de language-pack-it
       - name: Cache CPAN Modules
         uses: actions/cache@v3
         with:
           path: local
           key: perl-${{ steps.perl.outputs.perl-hash }}
       - run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends ExtUtils::MakeMaker List::MoreUtils::XS
-      # Remove Locale::TextDomain if https://github.com/gflohr/libintl-perl/issues/7 fixed and released.
-      - if: ${{ matrix.os == 'windows' }}
-        run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends Encode Win32::Console::ANSI Win32API::Net Win32::Locale Win32::ShellQuote DateTime::TimeZone::Local::Win32 Locale::TextDomain@1.31
+      - if: runner.os == 'Windows'
+        run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends Encode Win32::Console::ANSI Win32API::Net Win32::Locale Win32::ShellQuote DateTime::TimeZone::Local::Win32
       - run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends --cpanfile dist/cpanfile
       - run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends Test::Spelling Test::Pod Test::Pod::Coverage
       - name: prove
diff --git a/.github/workflows/perl.yml b/.github/workflows/perl.yml
index 22ddac38e..110aa8681 100644
--- a/.github/workflows/perl.yml
+++ b/.github/workflows/perl.yml
@@ -11,28 +11,30 @@ jobs:
   Perl:
     strategy:
       matrix:
-        os: [[🐧, ubuntu], [🍎, macos], [🪟, windows]]
+        os: [[🐧, ubuntu-latest], [🍎, macos-latest], [🪟, windows-latest]]
         perl: [ '5.38', '5.36', '5.34', '5.32', '5.30', '5.28', '5.26', '5.24', '5.22', '5.20', '5.18', '5.16', '5.14', '5.12' ]
         exclude:
           - { os: [🪟, windows], perl: '5.12' } # https://github.com/shogo82148/actions-setup-perl/issues/876
           - { os: [🪟, windows], perl: '5.14' } # https://github.com/shogo82148/actions-setup-perl/issues/881
     name: 🧅 Perl ${{ matrix.perl }} on ${{ matrix.os[0] }} ${{ matrix.os[1] }}
-    runs-on: ${{ matrix.os[1] }}-latest
+    runs-on: ${{ matrix.os[1] }}
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
         with: { perl-version: "${{ matrix.perl }}" }
       - run: perl -V
+      - if: runner.os == 'Linux'
+        name: Install Apt Packages
+        run: sudo apt-get install -qq language-pack-fr language-pack-en language-pack-de language-pack-it
       - name: Cache CPAN Modules
         uses: actions/cache@v3
         with:
           path: local
           key: perl-${{ steps.perl.outputs.perl-hash }}
-      # Remove Locale::TextDomain if https://github.com/gflohr/libintl-perl/issues/7 fixed and released.
-      - if: ${{ matrix.os[1] == 'windows' }}
-        run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends Encode Win32::Console::ANSI Win32API::Net Win32::Locale Win32::ShellQuote DateTime::TimeZone::Local::Win32 Locale::TextDomain@1.31
+      - if: runner.os == 'Windows'
+        run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends Encode Win32::Console::ANSI Win32API::Net Win32::Locale Win32::ShellQuote DateTime::TimeZone::Local::Win32
       - run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends --cpanfile dist/cpanfile
       - run: cpm install --verbose --show-build-log-on-failure --no-test --with-recommends Test::Spelling Test::Pod Test::Pod::Coverage
       - name: prove
diff --git a/.github/workflows/pg.yml b/.github/workflows/pg.yml
index c97c11ba7..39a81739f 100644
--- a/.github/workflows/pg.yml
+++ b/.github/workflows/pg.yml
@@ -15,7 +15,7 @@ jobs:
     name: 🐘 Postgres ${{ matrix.pg }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 9f5a1c1a0..f27f3336c 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -10,7 +10,7 @@ jobs:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
     - name: Check out the repo
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Setup Perl
       id: perl
       uses: shogo82148/actions-setup-perl@v1
diff --git a/.github/workflows/snowflake.yml b/.github/workflows/snowflake.yml
index 7dc089c56..45ddd26cc 100644
--- a/.github/workflows/snowflake.yml
+++ b/.github/workflows/snowflake.yml
@@ -11,7 +11,7 @@ jobs:
     name: ❄️ Snowflake
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Clients
         run: .github/ubuntu/snowflake.sh
       - name: Setup Perl
diff --git a/.github/workflows/sqlite.yml b/.github/workflows/sqlite.yml
index 4c0b758d1..12e1f4c16 100644
--- a/.github/workflows/sqlite.yml
+++ b/.github/workflows/sqlite.yml
@@ -16,7 +16,7 @@ jobs:
     name: 💡 SQLite ${{ matrix.sqlite }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
diff --git a/.github/workflows/vertica.yml b/.github/workflows/vertica.yml
index b524bbd3c..5b734dfbd 100644
--- a/.github/workflows/vertica.yml
+++ b/.github/workflows/vertica.yml
@@ -27,7 +27,7 @@ jobs:
         image: ${{ matrix.image }}:${{ matrix.version }}
         ports: [ 5433 ]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Clients
         run: .github/ubuntu/vertica.sh
       - name: Setup Perl
diff --git a/.github/workflows/yugabyte.yml b/.github/workflows/yugabyte.yml
index 9524be9c2..34c886e38 100644
--- a/.github/workflows/yugabyte.yml
+++ b/.github/workflows/yugabyte.yml
@@ -34,7 +34,7 @@ jobs:
         uses: jameshartig/yugabyte-db-action@master
         with:
           yb_image_tag: "${{ matrix.tag }}"
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Perl
         id: perl
         uses: shogo82148/actions-setup-perl@v1
diff --git a/.gitignore b/.gitignore
index 8033e00ee..a3efe757b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,7 +13,8 @@
 /_rpmbuild
 /target
 .build/
-*.mo
 .al
 /latest_changes.md
 /local/
+/LocaleData/
+/lib/LocaleData/
diff --git a/Changes b/Changes
index a3fa86e31..a0a5e75c6 100644
--- a/Changes
+++ b/Changes
@@ -22,6 +22,9 @@ Revision history for Perl extension App::Sqitch
        (#795)!
      - Fixed Oracle and Firebird test failures due to incorrect use of `chmod`.
        Thanks to Slaven Rezić for the report and the fix (#807)!
+     - Updated the locale configuration to fix issues in more recent versions
+       of Perl, and added tests to ensure that the sqitch CLI executes and
+       properly emits localized messages.
 
 1.4.0 2023-08-01T23:37:30Z
      - Fixed Snowflake warehouse and role setup to properly quote identifiers
diff --git a/bin/sqitch b/bin/sqitch
index e14a01115..89c77f22d 100755
--- a/bin/sqitch
+++ b/bin/sqitch
@@ -1,15 +1,6 @@
 #!perl -w -CAS
 
 # VERSION
-use POSIX qw(setlocale);
-BEGIN {
-    if ($^O eq 'MSWin32') {
-        require Win32::Locale;
-        setlocale POSIX::LC_ALL, Win32::Locale::get_locale();
-    } else {
-        setlocale POSIX::LC_ALL, '';
-    }
-}
+use locale;
 use App::Sqitch;
-
 exit App::Sqitch->go;
diff --git a/t/sqitch b/t/sqitch
index 350e7fc0a..cf9171dca 100755
--- a/t/sqitch
+++ b/t/sqitch
@@ -1,14 +1,6 @@
 #!/usr/bin/env perl -CAS
 
-use POSIX qw(setlocale);
-BEGIN {
-    if ($^O eq 'MSWin32') {
-        require Win32::Locale;
-        setlocale POSIX::LC_ALL, Win32::Locale::get_locale();
-    } else {
-        setlocale POSIX::LC_ALL, '';
-    }
-}
+use locale;
 use FindBin;
 use lib "$FindBin::Bin/../lib";
 use App::Sqitch;
diff --git a/xt/locale/LocaleData/de_DE/LC_MESSAGES/App-Sqitch.mo b/xt/locale/LocaleData/de_DE/LC_MESSAGES/App-Sqitch.mo
new file mode 100644
index 0000000000000000000000000000000000000000..b50dd0a33c7fc90fee01b7d92251e3986c8e2dd1
GIT binary patch
literal 209
zcmca7#4?ou2$+Ca28eZlm=%a^fEWY<fLIBL1A*8Sh)aN24Tx6(F(VLz^q~Ny>g4>~
z+{C<;S|x?dVuif?5`{#Cvc#Os6a}aRgHK{!dTC;Ms+B@YDwlJ9UP)?RiEc<`0Z^bM
zwW377ASW?1&srflBeAGBwZt|w#7)<NiviW(5{1;vJcZJ{^uv2{N;1<^ixiwv(^4~X
F7yx3`F@^vD

literal 0
HcmV?d00001

diff --git a/xt/locale/LocaleData/fr_FR/LC_MESSAGES/App-Sqitch.mo b/xt/locale/LocaleData/fr_FR/LC_MESSAGES/App-Sqitch.mo
new file mode 100644
index 0000000000000000000000000000000000000000..cf97378490e7c447122b916a301124b9e54b3dfd
GIT binary patch
literal 212
zcmca7#4?ou2$+Ca28eZlm=%a^fEWY<fLIBL1A*8Sh)aN26Npy<F(VLz^q~Ny>g4>~
z+{C<;S|x?dVuif?5`{#Cvc#Os6a}aRgHK{!dTC;Ms+B@o5tnm*UP)?RiEc<`0Z^bM
zwW377ASW?1&srflBeAGBwZt|w#7)<Nivii-JoVJ#5`}`qVujMYRG7J`5NlEy0PJ%y
AyZ`_I

literal 0
HcmV?d00001

diff --git a/xt/locale/LocaleData/it_IT/LC_MESSAGES/App-Sqitch.mo b/xt/locale/LocaleData/it_IT/LC_MESSAGES/App-Sqitch.mo
new file mode 100644
index 0000000000000000000000000000000000000000..5bb1d0263c744394887041a5517d887c37f59bc2
GIT binary patch
literal 207
zcmca7#4?ou2$+Ca28eZlm=%a^fEWY<fLIBL1A*8Sh)aN21&CJxF(VLz^q~Ny>g4>~
z+{C<;S|x?dVuif?5`{#Cvc#Os6a}aRgHK{!dTC;Ms+B@!372zzUP)?RiEc<`0Z^bM
zwW377ASW?1&srflBeAGBwZt|w#7)<Nivii-y!<?c!z&a@^FU?-?aGJPkk0@B0%0(Z

literal 0
HcmV?d00001

diff --git a/xt/locale/README.md b/xt/locale/README.md
new file mode 100644
index 000000000..10bbef37f
--- /dev/null
+++ b/xt/locale/README.md
@@ -0,0 +1,45 @@
+Sqitch Locale Test
+==================
+
+This directory contains the files necessary to test the Sqitch CLI to ensure it
+properly detects locale settings and emits translated messages. The
+[`po` directory here](./po/), unlike the canonical translations in the root `po`
+directory, contains only a few languages translating a single message:
+
+```
+"{command}" is not a valid command
+```
+
+The `LocaleData` directory contains the compiled forms of these dictionaries,
+and unlike the main dictionaries, these are committed to the repository. This
+allows the [OS](.github/workflows/os.yml) and [Perl](.github/workflows/os.yml)
+workflows to run without the overhead of compiling them (a PITA since `gettext`
+is hard to get on Windows and Dist::Zilla supports only more recent versions of
+Perl). If the messages need to change, recompile the dictionaries with these
+commands:
+
+```sh
+cpanm Dist::Zilla --notest
+dzil authordeps --missing | cpanm --notest
+dzil msg-compile -d xt/locale xt/locale/po/*.po
+```
+
+It's safe to ignore the warnings from `msg-compile`, as long as each translates
+a single message. For errors where it can't find `msgforat` or `gettext`, be
+sure that [gettext] is installed (readily available via `apt-get`, `yum`, or
+`brew`).
+
+Now run the test, which validates the output from [`bin/sqitch`](bin/sqitch):
+
+```sh
+prove -lv xt/locale/test-cli.t
+```
+
+If tests fail, be sure each of the locales is installed on your system.
+Apt-based systems, for example, require the relevant language packs:
+
+```sh
+sudo apt-get install -qq language-pack-fr language-pack-en language-pack-de language-pack-it
+```
+
+  [gettext]: https://www.gnu.org/software/gettext/
diff --git a/xt/locale/po/de_DE.po b/xt/locale/po/de_DE.po
new file mode 100644
index 000000000..4f54b5780
--- /dev/null
+++ b/xt/locale/po/de_DE.po
@@ -0,0 +1,6 @@
+msgid ""
+msgstr ""
+"Language: de\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+msgid "\"{command}\" is not a valid command"
+msgstr "\"{command}\" ist ein ungültiger Befehl"
diff --git a/xt/locale/po/fr_FR.po b/xt/locale/po/fr_FR.po
new file mode 100644
index 000000000..d7c1de0a0
--- /dev/null
+++ b/xt/locale/po/fr_FR.po
@@ -0,0 +1,6 @@
+msgid ""
+msgstr ""
+"Language: fr\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+msgid "\"{command}\" is not a valid command"
+msgstr "\"{command}\" n'est pas une commande valide"
diff --git a/xt/locale/po/it_IT.po b/xt/locale/po/it_IT.po
new file mode 100644
index 000000000..1400f0b37
--- /dev/null
+++ b/xt/locale/po/it_IT.po
@@ -0,0 +1,6 @@
+msgid ""
+msgstr ""
+"Language: it\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+msgid "\"{command}\" is not a valid command"
+msgstr "\"{command}\" non è un comando valido"
diff --git a/xt/locale/test-cli.t b/xt/locale/test-cli.t
new file mode 100644
index 000000000..65f7e5450
--- /dev/null
+++ b/xt/locale/test-cli.t
@@ -0,0 +1,36 @@
+#!/usr/bin/perl -w
+
+use strict;
+use warnings;
+use Test::More tests => 4;
+use File::Spec;
+use Capture::Tiny qw(:all);
+
+# Requires xt/locale/LocaleData; see xt/lcoale/README.md for details.
+my @cli = (qw(-Ilib -CAS -Ixt/locale), File::Spec->catfile(qw(bin sqitch)));
+
+# Each locale must be installed on the local system. Adding a new lang? Also add
+# the relevant language-pack-XX package to os.yml and perl.yml.
+for my $tc (
+    { lang => 'en_US', err => q{"nonesuch" is not a valid command} },
+    { lang => 'fr_FR', err => q{"nonesuch" n'est pas une commande valide} },
+    { lang => 'de_DE', err => q{"nonesuch" ist ein ungültiger Befehl} },
+    { lang => 'it_IT', err => q{"nonesuch" non è un comando valido} },
+) {
+    subtest $tc->{lang} || 'default' => sub {
+        local $ENV{LC_ALL} = "$tc->{lang}.UTF-8";
+
+        # Test successful run.
+        my ($stdout, $stderr, $exit) = capture { system $^X, @cli, 'help' };
+        is $exit >> 8, 0, 'Should have exited normally';
+        like $stdout, qr/\AUsage\b/, 'Should have usage statement in STDOUT';
+        is $stderr, '', 'Should have no STDERR';
+
+        # Test localized error.
+        ($stdout, $stderr, $exit) = capture { system $^X, @cli, 'nonesuch' };
+        is $exit >> 8, 2, 'Should have exit val 2';
+        is $stdout, '', 'Should have no STDOUT';
+        like $stderr, qr/\A\Q$tc->{err}/,
+            'Should have localized error message in STDERR';
+    };
+}