fix(#23): add pip version check

examples/exe_specific.py

@@ -7,6 +7,7 @@ it will generate a new vivenv.
 It may be important to require a exe specificty if you are frequently running
 different version of pythons and rely on c extension modules as in numpy.
 """
+
 __import__("viv").use("numpy", "plotext", track_exe=True)  # noqa
 
 import numpy as np

examples/frozen_import.py

@@ -6,6 +6,7 @@ This import statement was generated using
 Using viv freeze ensures future runs of this
 script will use the same essential environment
 """
+
 __import__("viv").use(
     "numpy==1.24.0",
     "pandas==1.5.2",

examples/sys_path.py

@@ -2,6 +2,7 @@
 """
 Embed the viv.py on the sys.path at runtime rather than using PYTHONPATH
 """
+
 import sys
 
 old_sys_path = sys.path.copy()  # noqa

pyproject.toml

@@ -42,7 +42,7 @@ test = [
   "sampleproject"
 ] 
 
-[tool.ruff]
+[tool.ruff.lint]
 select = ["E","F","I"]
 ignore = ["E402"]
 

src/viv/viv.py

@@ -1,9 +1,9 @@
 #!/usr/bin/env python3
 """viv isn't venv!
 
-  viv -h
+viv -h
-    OR
+  OR
-  __import__("viv").use("requests", "bs4")
+__import__("viv").use("requests", "bs4")
 """
 
 from __future__ import annotations
@@ -3877,6 +3877,20 @@ class Cli:
         )
 
 
+def _pip_check():
+    pip_version_requirement = ">=22.2"
+    if not shutil.which("pip"):
+        err_quit("viv requires pip to be installed")
+
+    # importing viv may have side effects I'm not aware of...
+    if Version((pip_version := __import__("pip").__version__)) not in SpecifierSet(
+        pip_version_requirement
+    ):
+        err_quit(
+            f"viv requires pip version {pip_version_requirement} but got {pip_version}"
+        )
+
+
 def _no_traceback_excepthook(
     exc_type: type[BaseException],
     exc_val: BaseException,
@@ -3888,6 +3902,7 @@ def _no_traceback_excepthook(
 
 def main() -> None:
     try:
+        _pip_check()
         viv = Viv()
         Cli(viv).run()
     except KeyboardInterrupt: