From cc00c24a0e2fc549206546807dc01d3fd16edaaa Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 26 Apr 2023 17:45:10 -0700
Subject: [PATCH 1/8] CI: Add testing for Musl Linux

---
 .github/workflows/unit-tests.yml | 35 ++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 69baa3ccd6f34..5e6c9c6c41ef6 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -241,6 +241,41 @@ jobs:
       group: ${{ github.event_name == 'push' && github.run_number || github.ref }}-32bit
       cancel-in-progress: true
 
+  Linux-Musl:
+    runs-on: ubuntu-22.04
+    container:
+      image: quay.io/pypa/musllinux_1_1_x86_64
+    steps:
+      - name: Checkout pandas Repo
+        # actions/checkout does not work since it requires node
+        run: |
+          git config --global --add safe.directory $PWD
+
+          if [ $GITHUB_EVENT_NAME != pull_request ]; then
+              git clone --recursive --branch=$GITHUB_REF_NAME https://github.com/${GITHUB_REPOSITORY}.git $GITHUB_WORKSPACE
+              git reset --hard $GITHUB_SHA
+          else
+              git clone --recursive https://github.com/${GITHUB_REPOSITORY}.git $GITHUB_WORKSPACE
+              git fetch origin $GITHUB_REF:my_ref_name
+              git checkout $GITHUB_BASE_REF
+              git -c user.email="you@example.com" merge --no-commit my_ref_name
+          fi
+      - name: Build environment and Run Tests
+        run: |
+          /opt/python/cp39-cp39/bin/python -m venv ~/virtualenvs/pandas-dev
+          . ~/virtualenvs/pandas-dev/bin/activate
+          python -m pip install --no-cache-dir --no-deps -U pip wheel setuptools
+          python -m pip install --no-cache-dir versioneer[toml] cython numpy python-dateutil pytz pytest>=7.0.0 pytest-xdist>=2.2.0 pytest-asyncio>=0.17 hypothesis>=6.46.1
+          python setup.py build_ext -q -j$(nproc)
+          python -m pip install --no-cache-dir --no-build-isolation --no-use-pep517 -e .
+          python -m pip list
+          export PANDAS_CI=1
+          python -m pytest -m 'not slow and not network and not clipboard and not single_cpu' pandas --junitxml=test-data.xml
+    concurrency:
+      # https://github.community/t/concurrecy-not-work-for-push/183068/7
+      group: ${{ github.event_name == 'push' && github.run_number || github.ref }}-musl
+      cancel-in-progress: true
+
   python-dev:
     # This job may or may not run depending on the state of the next
     # unreleased Python version. DO NOT DELETE IT.

From ce109341e163a4db9e3219979f9ae05b0c2693e3 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 09:36:24 -0700
Subject: [PATCH 2/8] Install locale

---
 .github/workflows/unit-tests.yml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 5e6c9c6c41ef6..578e5030f36a0 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -260,6 +260,11 @@ jobs:
               git checkout $GITHUB_BASE_REF
               git -c user.email="you@example.com" merge --no-commit my_ref_name
           fi
+      - name: Configure System Packages
+        run: |
+          apk update
+          apk add musl-locales
+          apk add lang
       - name: Build environment and Run Tests
         run: |
           /opt/python/cp39-cp39/bin/python -m venv ~/virtualenvs/pandas-dev

From 1a6344b5b6bc963735618485d239a02d1abe89fe Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 13:21:04 -0700
Subject: [PATCH 3/8] Add loc path

---
 .github/workflows/unit-tests.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 578e5030f36a0..08f42a27babed 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -262,9 +262,9 @@ jobs:
           fi
       - name: Configure System Packages
         run: |
+          export MUSL_LOCPATH=/usr/share/i18n/locales/musl
           apk update
-          apk add musl-locales
-          apk add lang
+          apk add musl-locales musl-locales-lang
       - name: Build environment and Run Tests
         run: |
           /opt/python/cp39-cp39/bin/python -m venv ~/virtualenvs/pandas-dev

From 1ed91b7d1794f68d8818bf18c2880b2fdb271515 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 13:30:13 -0700
Subject: [PATCH 4/8] set tz too

---
 .github/workflows/unit-tests.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 08f42a27babed..5a87819e209bb 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -263,6 +263,7 @@ jobs:
       - name: Configure System Packages
         run: |
           export MUSL_LOCPATH=/usr/share/i18n/locales/musl
+          export TZ=GMT
           apk update
           apk add musl-locales musl-locales-lang
       - name: Build environment and Run Tests

From cc882db3c169a4babd2b3a71f448f576f548d598 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 14:57:03 -0700
Subject: [PATCH 5/8] Skip one test for musl, use more standard tz for musl

---
 .github/workflows/unit-tests.yml         |  1 -
 pandas/compat/__init__.py                |  2 ++
 pandas/compat/_constants.py              |  3 +++
 pandas/tests/config/test_localization.py | 16 +++++++++++++++-
 pandas/tests/tslibs/test_parsing.py      |  2 +-
 5 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 5a87819e209bb..08f42a27babed 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -263,7 +263,6 @@ jobs:
       - name: Configure System Packages
         run: |
           export MUSL_LOCPATH=/usr/share/i18n/locales/musl
-          export TZ=GMT
           apk update
           apk add musl-locales musl-locales-lang
       - name: Build environment and Run Tests
diff --git a/pandas/compat/__init__.py b/pandas/compat/__init__.py
index 3d7589bf67ee2..00957c45a7fbe 100644
--- a/pandas/compat/__init__.py
+++ b/pandas/compat/__init__.py
@@ -16,6 +16,7 @@
 
 from pandas.compat._constants import (
     IS64,
+    ISMUSL,
     PY310,
     PY311,
     PYPY,
@@ -160,6 +161,7 @@ def get_lzma_file() -> type[pandas.compat.compressors.LZMAFile]:
     "pa_version_under9p0",
     "pa_version_under11p0",
     "IS64",
+    "ISMUSL",
     "PY310",
     "PY311",
     "PYPY",
diff --git a/pandas/compat/_constants.py b/pandas/compat/_constants.py
index 1d522a5b4cd09..1d7fe23b3d2ea 100644
--- a/pandas/compat/_constants.py
+++ b/pandas/compat/_constants.py
@@ -9,16 +9,19 @@
 
 import platform
 import sys
+import sysconfig
 
 IS64 = sys.maxsize > 2**32
 
 PY310 = sys.version_info >= (3, 10)
 PY311 = sys.version_info >= (3, 11)
 PYPY = platform.python_implementation() == "PyPy"
+ISMUSL = "musl" in (sysconfig.get_config_var("HOST_GNU_TYPE") or "")
 
 
 __all__ = [
     "IS64",
+    "ISMUSL",
     "PY310",
     "PY311",
     "PYPY",
diff --git a/pandas/tests/config/test_localization.py b/pandas/tests/config/test_localization.py
index 6474177261b91..8ea3085116eaa 100644
--- a/pandas/tests/config/test_localization.py
+++ b/pandas/tests/config/test_localization.py
@@ -10,6 +10,8 @@
     set_locale,
 )
 
+from pandas.compat import ISMUSL
+
 import pandas as pd
 
 _all_locales = get_locales()
@@ -46,7 +48,19 @@ def test_can_set_locale_valid_set(lc_var):
     assert before_locale == after_locale
 
 
-@pytest.mark.parametrize("lc_var", (locale.LC_ALL, locale.LC_CTYPE, locale.LC_TIME))
+@pytest.mark.parametrize(
+    "lc_var",
+    (
+        locale.LC_ALL,
+        pytest.param(
+            locale.LC_CTYPE,
+            marks=pytest.mark.skipif(
+                ISMUSL, reason="MUSL allows setting invalid LC_CTYPE."
+            ),
+        ),
+        locale.LC_TIME,
+    ),
+)
 def test_can_set_locale_invalid_set(lc_var):
     # Cannot set an invalid locale.
     before_locale = _get_current_locale(lc_var)
diff --git a/pandas/tests/tslibs/test_parsing.py b/pandas/tests/tslibs/test_parsing.py
index 6500afdf87beb..d514acfa1b685 100644
--- a/pandas/tests/tslibs/test_parsing.py
+++ b/pandas/tests/tslibs/test_parsing.py
@@ -25,7 +25,7 @@ def test_parsing_tzlocal_deprecated():
     msg = "Pass the 'tz' keyword or call tz_localize after construction instead"
     dtstr = "Jan 15 2004 03:00 EST"
 
-    with tm.set_timezone("US/Eastern"):
+    with tm.set_timezone("EST5EDT"):
         with tm.assert_produces_warning(FutureWarning, match=msg):
             res, _ = parse_datetime_string_with_reso(dtstr)
 

From 0b6d0632d6cdc2452a46c9b3298953439ba0cf13 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 16:50:13 -0700
Subject: [PATCH 6/8] Correct skips for MUSL

---
 .github/workflows/unit-tests.yml         |  7 +++++--
 pandas/tests/config/test_localization.py |  6 +++---
 pandas/tests/tslibs/test_parsing.py      | 11 +++++++++--
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 08f42a27babed..3c5e776d006c2 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -265,7 +265,7 @@ jobs:
           export MUSL_LOCPATH=/usr/share/i18n/locales/musl
           apk update
           apk add musl-locales musl-locales-lang
-      - name: Build environment and Run Tests
+      - name: Build environment
         run: |
           /opt/python/cp39-cp39/bin/python -m venv ~/virtualenvs/pandas-dev
           . ~/virtualenvs/pandas-dev/bin/activate
@@ -273,7 +273,10 @@ jobs:
           python -m pip install --no-cache-dir versioneer[toml] cython numpy python-dateutil pytz pytest>=7.0.0 pytest-xdist>=2.2.0 pytest-asyncio>=0.17 hypothesis>=6.46.1
           python setup.py build_ext -q -j$(nproc)
           python -m pip install --no-cache-dir --no-build-isolation --no-use-pep517 -e .
-          python -m pip list
+          python -m pip list --no-cache-dir
+
+      - name: Run Tests
+          . ~/virtualenvs/pandas-dev/bin/activate
           export PANDAS_CI=1
           python -m pytest -m 'not slow and not network and not clipboard and not single_cpu' pandas --junitxml=test-data.xml
     concurrency:
diff --git a/pandas/tests/config/test_localization.py b/pandas/tests/config/test_localization.py
index 8ea3085116eaa..3907f557d1075 100644
--- a/pandas/tests/config/test_localization.py
+++ b/pandas/tests/config/test_localization.py
@@ -52,13 +52,13 @@ def test_can_set_locale_valid_set(lc_var):
     "lc_var",
     (
         locale.LC_ALL,
+        locale.LC_CTYPE,
         pytest.param(
-            locale.LC_CTYPE,
+            locale.LC_TIME,
             marks=pytest.mark.skipif(
-                ISMUSL, reason="MUSL allows setting invalid LC_CTYPE."
+                ISMUSL, reason="MUSL allows setting invalid LC_TIME."
             ),
         ),
-        locale.LC_TIME,
     ),
 )
 def test_can_set_locale_invalid_set(lc_var):
diff --git a/pandas/tests/tslibs/test_parsing.py b/pandas/tests/tslibs/test_parsing.py
index d514acfa1b685..587527c2058d7 100644
--- a/pandas/tests/tslibs/test_parsing.py
+++ b/pandas/tests/tslibs/test_parsing.py
@@ -14,18 +14,25 @@
     strptime,
 )
 from pandas._libs.tslibs.parsing import parse_datetime_string_with_reso
+from pandas.compat import (
+    ISMUSL,
+    is_platform_windows,
+)
 import pandas.util._test_decorators as td
 
 import pandas._testing as tm
 
 
-@td.skip_if_windows
+@pytest.mark.skipif(
+    is_platform_windows() or ISMUSL,
+    reason="TZ setting incorrect on Windows and MUSL Linux",
+)
 def test_parsing_tzlocal_deprecated():
     # GH#50791
     msg = "Pass the 'tz' keyword or call tz_localize after construction instead"
     dtstr = "Jan 15 2004 03:00 EST"
 
-    with tm.set_timezone("EST5EDT"):
+    with tm.set_timezone("US/Eastern"):
         with tm.assert_produces_warning(FutureWarning, match=msg):
             res, _ = parse_datetime_string_with_reso(dtstr)
 

From 1beb2adaced57ffd35fd7e59ded0262ab90a4925 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 18:10:22 -0700
Subject: [PATCH 7/8] Do less stuff during install

---
 .github/workflows/unit-tests.yml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 3c5e776d006c2..cdf0666d08185 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -262,9 +262,8 @@ jobs:
           fi
       - name: Configure System Packages
         run: |
-          export MUSL_LOCPATH=/usr/share/i18n/locales/musl
           apk update
-          apk add musl-locales musl-locales-lang
+          apk add musl-locales
       - name: Build environment
         run: |
           /opt/python/cp39-cp39/bin/python -m venv ~/virtualenvs/pandas-dev

From 92a73aa9f603e31af1895c69becddd933b89a391 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Thu, 27 Apr 2023 19:24:36 -0700
Subject: [PATCH 8/8] syntax error

---
 .github/workflows/unit-tests.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index cdf0666d08185..553d3e7d568a1 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -275,6 +275,7 @@ jobs:
           python -m pip list --no-cache-dir
 
       - name: Run Tests
+        run: |
           . ~/virtualenvs/pandas-dev/bin/activate
           export PANDAS_CI=1
           python -m pytest -m 'not slow and not network and not clipboard and not single_cpu' pandas --junitxml=test-data.xml