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Shopify / bootsnap

Boot large Ruby/Rails apps faster
MIT License
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Bootsnap changes `require`'s memoizing behavior vs vanilla Ruby #264

Open nelhage-stripe opened 5 years ago

nelhage-stripe commented 5 years ago

In vanilla MRI, if you require a file via absolute path, which is also present on $LOAD_PATH, MRI internally caches it under its relative path, and will allow it to satisfy future require "relative/path" calls, even if such a call would otherwise resolve to a file earlier in $LOAD_PATH.

bootsnap does not properly implement this behavior, resulting in a difference in behavior versus MRI's require, which turned out to break our application. This is honestly an odd behavior for us to be relying on and I'm going to attempt to work around it locally, but I wanted to report the bug for visibility.

This behavior is rather unclear to me from the Ruby documentation, and arguably this could be reported as an MRI bug instead.

I've built a simple reproducer that demonstrates different behavior under bootsnap and without here: https://github.com/nelhage-stripe/bootsnap-reproducer

burke commented 5 years ago

Thanks for the report, this is news to me! I'm open to anyone taking a run at fixing this but I'm unlikely to find time to work on it myself.

aldodelgado commented 5 years ago

I am also experiencing this issue. Does any have any suggestions on a work around until there is a proper fix?

nelhage commented 5 years ago

I was able to workaround by switching a $LOAD_PATH << new_dir to $LOAD_PATH.unshift(new_dir) in the location that added the problematic directory, but this isn't necessarily applicable to all cases.