MyPy crashes if file has changes not yet written to disc

[macdjord]

Step 1: Are you in the right place?

• I have verified there are no duplicate active or recent bugs, questions, or requests
• I have verified that I am using the latest version of the plugin.

Step 2: Describe your environment

• Plugin version: 0.16.0
• PyCharm/IDEA version: PyCharm 2023.2.1 (Community Edition)
• Mypy version: mypy 1.5.1 (compiled: yes)

Step 3: Describe the problem:

Steps to reproduce:

1. I open a file and run a scan (either manually or by letting the MyPy inspection run). The scan succeeds and reports various issues.
2. I make any change to the file whatsoever and then rerun the scan (again, either manually or automatically). The scan fails.
3. I tab out of PyCharm, causing it to write the changes to disc. When I tab back in, the scan works again.

Observed Results:

Note: I turned off the MyPy inspection for this test, but it has the same error.

1. Run manual scan of unchanged file (successful):
   • idea.log:

     2023-09-19 18:32:06,373 [505670596]   INFO - #com.leinardi.pycharm.mypy.MypyPlugin - Scanning current file(s).
     2023-09-19 18:32:06,569 [505670792]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Detected Mypy path: C:\Python311\Scripts\mypy.exe
     2023-09-19 18:32:07,199 [505671422]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Detected Mypy path: C:\Python311\Scripts\mypy.exe
     2023-09-19 18:32:07,199 [505671422]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Running command: C:\Python311\Scripts\mypy.exe --show-column-numbers --follow-imports silent --config-file C:\Users\jordan.macdonald\source\sentinel.git\.mypy.ini C:\Users\jordan.macdonald\source\sentinel.git\sentinel-python-base\lib\json_transcoder\_from_json.py
     2023-09-19 18:32:12,327 [505676550]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities to files
     

2. Edit file, run manual scan (error):
   • idea.log:

     2023-09-19 18:32:33,030 [505697253]   INFO - #com.leinardi.pycharm.pylint.plapi.PylintRunner - Detected Pylint path: C:\Python311\Scripts\pylint.exe
     2023-09-19 18:32:34,215 [505698438]   INFO - #com.leinardi.pycharm.pylint.plapi.PylintRunner - Detected Pylint path: C:\Python311\Scripts\pylint.exe
     2023-09-19 18:32:35,513 [505699736]   INFO - #com.leinardi.pycharm.pylint.plapi.PylintRunner - Detected Pylint path: C:\Python311\Scripts\pylint.exe
     2023-09-19 18:32:38,981 [505703204]   INFO - #com.leinardi.pycharm.mypy.MypyPlugin - Scanning current file(s).
     2023-09-19 18:32:39,233 [505703456]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Detected Mypy path: C:\Python311\Scripts\mypy.exe
     2023-09-19 18:32:39,803 [505704026]   INFO - #com.leinardi.pycharm.pylint.plapi.PylintRunner - Detected Pylint path: C:\Python311\Scripts\pylint.exe
     2023-09-19 18:32:39,836 [505704059]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Detected Mypy path: C:\Python311\Scripts\mypy.exe
     2023-09-19 18:32:39,837 [505704060]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Running command: C:\Python311\Scripts\mypy.exe --show-column-numbers --follow-imports silent --config-file C:\Users\jordan.macdonald\source\sentinel.git\.mypy.ini C:\Users\JORDAN~1.MAC\AppData\Local\Temp\csi-029\sentinel-python-base\lib\json_transcoder\_from_json.py
     2023-09-19 18:32:40,999 [505705222]   INFO - #com.leinardi.pycharm.pylint.plapi.PylintRunner - Detected Pylint path: C:\Python311\Scripts\pylint.exe
     2023-09-19 18:32:41,203 [505705426]   INFO - #c.i.o.a.i.PopupMenuPreloader - 2009 ms since showing to preload popup menu '' at 'StructureViewPopup(preload-bgt)' in 1 ms
     2023-09-19 18:32:42,118 [505706341]   INFO - #com.leinardi.pycharm.pylint.plapi.PylintRunner - Detected Pylint path: C:\Python311\Scripts\pylint.exe
     2023-09-19 18:33:05,301 [505729524]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities to files
     

   • Notifications panel:

     Mypy Plugin: Mypy exited abnormally
     

   • Notifications panel:

     Unexpected Exception Caught
     
     The scan failed due to an exception: Mypy failed with code 2 com.leinardi.pycharm.mypy.exception.MypyToolException: Mypy failed with code 2
       at com.leinardi.pycharm.mypy.mpapi.MypyRunner.runMypy(MypyRunner.java:323)
       at com.leinardi.pycharm.mypy.mpapi.MypyRunner.scan(MypyRunner.java:262)
       at com.leinardi.pycharm.mypy.checker.ScanFiles.scan(ScanFiles.java:108)
       at com.leinardi.pycharm.mypy.checker.ScanFiles.checkFiles(ScanFiles.java:99)
       at com.leinardi.pycharm.mypy.checker.ScanFiles.call(ScanFiles.java:73)
       at com.leinardi.pycharm.mypy.checker.ScanFiles.call(ScanFiles.java:45)
       at com.intellij.openapi.application.impl.ApplicationImpl$3.call(ApplicationImpl.java:303)
       at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
       at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
       at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
       at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:702)
       at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:699)
       at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
       at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:699)
       at java.base/java.lang.Thread.run(Thread.java:833)
     

3. Tab out of PyCharm, tab back in, run manual scan (successful):
   • idea.log:

     2023-09-19 18:33:29,567 [505753790]   INFO - #com.leinardi.pycharm.mypy.MypyPlugin - Scanning current file(s).
     2023-09-19 18:33:29,752 [505753975]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Detected Mypy path: C:\Python311\Scripts\mypy.exe
     2023-09-19 18:33:30,284 [505754507]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Detected Mypy path: C:\Python311\Scripts\mypy.exe
     2023-09-19 18:33:30,284 [505754507]   INFO - #com.leinardi.pycharm.mypy.mpapi.MypyRunner - Running command: C:\Python311\Scripts\mypy.exe --show-column-numbers --follow-imports silent --config-file C:\Users\jordan.macdonald\source\sentinel.git\.mypy.ini C:\Users\jordan.macdonald\source\sentinel.git\sentinel-python-base\lib\json_transcoder\_from_json.py
     2023-09-19 18:33:34,289 [505758512]   INFO - #c.i.w.i.i.j.s.JpsGlobalModelSynchronizerImpl - Saving global entities to files
     

Note: The notification panel does not give any details, nor report what, if anything, MyPy reported to STDERR before dying. (Or at least I can't find any way to view that information if it does.)

Expected Results:

No error should occur.

Relevant Code:

Notes:

When I try running C:\Python311\Scripts\mypy.exe --show-column-numbers --follow-imports silent --config-file C:\Users\jordan.macdonald\source\sentinel.git\.mypy.ini C:\Users\JORDAN~1.MAC\AppData\Local\Temp\csi-029\sentinel-python-base\lib\json_transcoder\_from_json.py manually in a command window, it fails with this message: mypy: can't read file 'C:\Users\JORDAN~1.MAC\AppData\Local\Temp\csi-029\sentinel-python-base\lib\json_transcoder\_from_json.py': No such file or directory

However, I'm not sure if that's the actual underlying error that happened at the time or if PyCharm just deleted the temporary file after it was done with it.