I downloaded the exact forge version in your build.gradle in case that was the problem, but it still persisted.
When running "gradlew setupDecompWorkspace", I get the following error below

I'm just trying to make a super small edit for my personal use (Making Secure class and it's login method public so I can call it when automatically re-logging in with another mod.) So nothing but adding 2 words in two places of the code.

But I'm getting stuck on the fact it errors out due to keyStoreAlias property.

EDIT: I would give stacktrace but I'm not sure where that logs to. I tried re-directing command line output by using "gradlew setupDecompWorkspace --stacktrace > output.txt", but it didn't log anything besides basically saying build failed, all the rest still went to the CMD prompt instead of the text file.

While ReAuth will not be offering fully automatic retries, version 3.9.0 now has a "Login as and Retry" Button on the Connection error Screen. While v3.9.0 is currently only available for 1.16 (Forge and Fabric) backports to older Mc Versions will follow soonish.

That seems to be caused by my jar-signing code i added to the build.gadle file just delete everything below this line for now.
You will also have to make an edit to the Main class to disable the signature check.

Im intrigued as to what your usecase or the other mod could be, can you elaborate on those? I might be able to incorporate this into ReAuth by default.

Keep in mind that this Project is visible source only and you are not permitted to distribute derivatives ie. the modified version of this mod.