Reorganize bin/lein and bin/lein-pkg to make coordination easier

[hypirion]

We've had some changes in lein that haven't been moved over to lein-pkg.

[TrangPham]

What are the changes that need to be moved over?
Would this involve making the lein-pkg pass in Tiered in the LEIN_JVM_OPTS? https://github.com/technomancy/leiningen/blob/master/bin/lein-pkg#L107

[hypirion]

Hi!

I have noted down the patch #1918 mostly, but yes, the Tiered stuff in LEIN_JVM_OPTS would be good to have fixed too. There also seems to be a command line argument mismatch – lein-pkg has for example -client -XX:+TieredCompilation as arguments when calling LEIN_JAVA_CMD, and lein proper has an additional -Dmaven.wagon.rto=10000. I believe those arguments should be identical.

Happy to take patches for this, they don't have to fix all the differences between lein-pkg and lein.

[TrangPham]

lein-pkg and lein seem to have a lot of similar code. Is there a reason why a common included bash script is not used? This would help keep it DRY.

[hypirion]

Yeah, it's unfortunate that lein and lein-pkg doesn't share code. One of the issues is that people need to be able to download lein standalone from the git repo, whereas some downstream package managers (like Homebrew) uses lein-pkg directly from the repo. Consequently lein and lein-pkg must be standalone scripts.

I'd love some way to have the shared code in a single file and some script that regenerates lein and lein-pkg, but that may be harder to understand. Happy to take suggestions on how to make this better though, maybe it's not as bad as I expect it would be.

[TrangPham]

Option 1:
One solution is to use bash to source a common file: http://stackoverflow.com/questions/192292/bash-how-best-to-include-other-scripts

Though this may not work if downstream package managers don't grab any of the other files.

Option 2:
A simple generation technique would to have a common file, a gen file for lein and a gen file for lein-pkg. The gen files would contain the unique code for lein and lein-pkg respectively. Then use a simple script that copies the common file over to lein and lein-pkg and appends the corresponding gen file to it.

ie.

cp common lein
cat gen_lein >> lein

Option 3:
Just reorganize the code in lein and lein-pkg such that the common code is at the top and commented as common code. Ideally this section would be the same line for line such that we could use git diff to ensure they are the same.

This would be like option 2 but with out the script to generate. This would keep the files completely separate, but increase the maintainability.

[hypirion]

Option 1 would not work – it would make lein installation more difficult than described at http://leiningen.org. That leaves us with option 2 and 3.

From experience, option 2 tends to create somewhat confusing scripts. But if it's done properly and is well documented that is likely to be the best way to ensure that lein-pkg and lein is synced.

I think option 3 would be the most realistic one if possible.

[hypirion]

I'm happy with the current situation for 2.6.0, but I'm keeping this open to consider options to automatically sync changes.