Use env to determine python3 location

[juhannc]

In general, it is recommended to use #!/usr/bin/env python3 as the shebang instead of the hardcoded !#/usr/bin/python3.
See https://stackoverflow.com/a/5709632 for more information.
Related to JabRef-Browser-Extension #177, especially this comment.

• Change in CHANGELOG.md described (if applicable)
• Tests created for changes (if applicable)
• Manually tested changed features in running JabRef (always required)
• Screenshots added in PR description (for UI changes)
• Checked documentation: Is the information available and up to date? If not created an issue at https://github.com/JabRef/user-documentation/issues or, even better, submitted a pull request to the documentation repository.

[tobiasdiez]

Thanks, that's a nice improvement indeed. Could you please also change the mac version of the script https://github.com/JabRef/jabref/blob/master/buildres/mac/jabrefHost.py and add a short entry to the changelog.

[juhannc]

Thanks, that's a nice improvement indeed. Could you please also change the mac version of the script https://github.com/JabRef/jabref/blob/master/buildres/mac/jabrefHost.py and add a short entry to the changelog.

@tobiasdiez Done! Listed the change under Changed, hope thats fine :)

[LyzardKing]

I thought we had changed this already. Great change.
The mac version fails to run with env (it depends where python comes from, system or brew)

[juhannc]

I see, I was only able to test it on my mac with Python installed via brew.
Any way to fix it for non-brew systems?

[LyzardKing]

I tried but there were too many error reports.
I'm not sure if there's a way to do it properly

[tobiasdiez]

So on mac we still should use !#/usr/bin/python3 ?

[LyzardKing]

The issue was looked at here: JabRef/JabRef-Browser-Extension#177
If it works we should leave the mac one as is

[juhannc]

I just confirmed on a brand new Mac.
Using /usr/bin/python3 works, but usr/bin/env python3 would require the XCode command line developer tools.
I'll revert I reverted the changes for macOS and then the PR would be is now ready from my side.

[tobiasdiez]

Thanks, and sorry for the misleading suggestion from my side.