fix(internal): catch possible OSError when calling platform.libc_ver() (backport #4828) (#4832)

## Description

When calling `platform.libc_ver()` on an unsupported system it can raise
an `OSError`.

This change adds exception handling for `OSError` and regression test.

## Reviewer Checklist
- [x] Title is accurate.
- [x] Description motivates each change.
- [x] No unnecessary changes were introduced in this PR.
- [x] Avoid breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes unless absolutely necessary.
- [x] Tests provided or description of manual testing performed is
included in the code or PR.
- [x] Release note has been added and follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/contributing.html#Release-Note-Guidelines),
or else `changelog/no-changelog` label added.
- [x] All relevant GitHub issues are correctly linked.
- [x] Backports are identified and tagged with Mergifyio.

Author: brettlangdon

ddtrace/internal/telemetry/data.py

@@ -33,11 +33,28 @@ def _get_container_id():
 def _get_os_version():
     # type: () -> str
     """Returns the os version for applications running on Unix, Mac or Windows 32-bit"""
-    mver, _, _ = platform.mac_ver()
-    _, wver, _, _ = platform.win32_ver()
-    _, lver = platform.libc_ver()
+    try:
+        mver, _, _ = platform.mac_ver()
+        if mver:
+            return mver
+
+        _, wver, _, _ = platform.win32_ver()
+        if wver:
+            return wver
+
+        # This is the call which is more likely to fail
+        #
+        # https://docs.python.org/3/library/platform.html#unix-platforms
+        #   Note that this function has intimate knowledge of how different libc versions add symbols
+        #   to the executable is probably only usable for executables compiled using gcc.
+        _, lver = platform.libc_ver()
+        if lver:
+            return lver
+    except OSError:
+        # We were unable to lookup the proper version
+        pass
 
-    return mver or wver or lver or ""
+    return ""
 
 
 @cached()

releasenotes/notes/fix-telemetry-platform-libc-ver-call-8872bde91bcc8765.yaml

@@ -0,0 +1,4 @@
+---
+fixes:
+  - |
+    telemetry: This fix resolves an issue when we try to fetch ``platform.libc_ver()`` on an unsupported system.

tests/telemetry/test_data.py

@@ -108,10 +108,10 @@ def test_get_host_info():
 @pytest.mark.parametrize(
     "mac_ver,win32_ver,libc_ver,expected",
     [
-        ((None, None, None), (None, "4.1.6", None, None), (None, None), "4.1.6"),
-        (("3.5.6", None, None), (None, "", None, None), (None, None), "3.5.6"),
-        ((None, None, None), (None, None, None, None), (None, "1.2.7"), "1.2.7"),
-        ((None, None, None), (None, None, None, None), (None, None), ""),
+        (("", "", ""), ("", "4.1.6", "", ""), ("", ""), "4.1.6"),
+        (("3.5.6", "", ""), ("", "", "", ""), ("", ""), "3.5.6"),
+        (("", "", ""), ("", "", "", ""), ("", "1.2.7"), "1.2.7"),
+        (("", "", ""), ("", "", "", ""), ("", ""), ""),
     ],
 )
 def test_get_os_version(mac_ver, win32_ver, libc_ver, expected):
@@ -125,6 +125,32 @@ def test_get_os_version(mac_ver, win32_ver, libc_ver, expected):
                 assert _get_os_version() == expected
 
 
+@pytest.mark.parametrize(
+    "mac_ver,win32_ver,expected",
+    [
+        # We are on a unix system that raised an OSError
+        (("", "", ""), ("", "", "", ""), ""),
+        # We are on macOS, we never call platform.libc_ver(), so success
+        (("3.5.6", "", ""), ("", "", "", ""), "3.5.6"),
+        # We are on a Windows machine, we never call platform.libc_ver(), so success
+        (("", "", ""), ("", "4.1.6", "", ""), "4.1.6"),
+    ],
+)
+def test_get_os_version_os_error(mac_ver, win32_ver, expected):
+    """regression test for platform.libc_ver() raising an OSError on Windows/unsupported machine"""
+    with mock.patch("platform.mac_ver") as macos:
+        macos.return_value = mac_ver
+
+        with mock.patch("platform.win32_ver") as win32:
+            win32.return_value = win32_ver
+
+            # Cause platform.libc_ver() to raise an OSError
+            with mock.patch("platform.libc_ver") as libc:
+                libc.side_effect = OSError
+
+                assert _get_os_version() == expected
+
+
 def test_get_container_id_when_container_exists():
     """
     validates the return value of _get_container_id when get_container_info()