Check whether pip module exists in shared lib before performing any actions

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## dev
 
+- Use virtual environment's Python to check for pip's availability during reinstalling process
 - Drop support for Python 3.7
 - Make usage message in `pipx run` show `package_or_url`, so extra will be printed out as well
 - Add `--force-reinstall` to pip arguments when `--force` was passed

src/pipx/commands/reinstall.py

@@ -1,4 +1,3 @@
-import importlib.util
 import sys
 from pathlib import Path
 from typing import List, Sequence
@@ -17,7 +16,7 @@
     ExitCode,
 )
 from pipx.emojis import error, sleep
-from pipx.util import PipxError
+from pipx.util import PipxError, run_subprocess
 from pipx.venv import Venv, VenvContainer
 
 
@@ -47,7 +46,13 @@ def reinstall(
     else:
         package_or_url = venv.main_package_name
 
-    if importlib.util.find_spec("pip") is None:
+    check_pip = "import importlib.util; print(importlib.util.find_spec('pip'))"
+    out = run_subprocess(
+        [venv.python_path, "-c", check_pip],
+        capture_stderr=False,
+        log_cmd_str="<checking pip's availability>",
+    ).stdout.strip()
+    if out == "None":
         raise PipxError(
             f"Can not find pip. You may encounter issues uninstalling packages. "
             f"Remove {PIPX_SHARED_LIBS} and run 'pipx reinstall-all' to fix them."