Briefcase download an incomplete rcedit-x64.exe lead to "OSerror: [WinError 193] %1 is not a valid win32 application"

[baozidai]

Describe the bug

The first time to run briefcase build, it downloads a file "rcedit-x64.exe" to path C:\Users<YourUsername>\AppData\Local\BeeWare\briefcase\Cache\tools (THE_TOOLS_PATH).

In some way, I get an incomplete one, so that I can't build my application. Then the problem is:
There is no way to make sure you get a healthy "rcedit-x64.exe", or if you get a bad one, the trackback don't show you any thing about "rcedit-x64.exe", and this is hard to know the real problem.

Steps to reproduce

1. Make sure there is not a file "rcedit-x64.exe" or "rcedit-x64.exe" in THE_TOOLS_PATH above. If there is one, delete it.
2. Create a new briefcase project
3. Create scaffold via briefcase create
4. Then briefcase build, it should not find the rcedit file and start downloading "rcedit-x64.exe". If your have a bad Internet, you can get an incomplete "rcedit-x64.exe" in THE_TOOLS_PATH.
5. "OSerror: [WinError 193] %1 is not a valid win32 application" will occur.

Expected behavior

A perfect build process.

Screenshots

Environment

• Operating System: Windows 10 21H2
• Python version: 3.11.2
• Software versions:
  • Briefcase: 0.3.13
  • Toga: 0.3.0

Logs

I've fixed this so I can't get a bug log.

Additional context

How to fix

if you're facing this, download a rcedit-x64.exe from rcedit. Replace it in C:\Users<YourUsername>\AppData\Local\BeeWare\briefcase\Cache\tools

[rmartin16]

We put a mitigation in place to to prevent a partial tool download from persisting in the Briefcase tools cache.

Any time Briefcase fails, it puts the log file in to the logs directory of your project. If it is still available for the briefcase build run that did the download, I would appreciate you uploading here so we can understand what went wrong.

[baozidai]

briefcase.2023_04_01-22_26_05.build.log (first it try to download the tool, but failed)
briefcase.2023_04_01-22_35_35.build.log (Next build, cause there is an incomplete one rcedit, OsError occur)

[rmartin16]

Thank you, @baozidai; I appreciate the additional information. This helps me to understand a bit of what happened.

In the first log from 22:26:05, the download failure occurs from just attempting to setup the HTTPs connection with github.com and before actually downloading any data and before the rcedit-x64.exe file is created in the Briefcase cache in AppData.

In the 22:35:35 log file, though, you can see that an attempt is made to download rcedit-x64.exe again and after ~73 seconds, it ostensibly succeeds.....yet, when rcedit-x64.exe is used, Windows does not think it is a valid executable.

Given the download apparently averaged ~18KB/s and there was at least one previous failure to even connect to github.com, this certainly seems to be distressed connection...or one that is potentially being throttled. I'm not sure what the mechanism would be for a download to finish successfully....yet with different data than was requested; the underlying protocols use at least basic hashing for data integrity.

I think my most plausible guess is rcedit-x64.exe was not actually downloaded from github.com; perhaps something else entirely was returned (like a proxy redirection web page for instance) or perhaps the connection was interrupted but terminated properly somehow.

This does reveal that more can be done to verify the integrity or perhaps identity of the downloaded tools. Maybe even catching errors like this and asking the user if they want to "clear the tool cache" or something to see if that mitigates an error they're seeing.