issue-link js-issue-link" data-error-text="Failed to load title" data-id="1125898943" data-permission-text="Title is private" data-url="https://github.com/Shopify/bootsnap/issues/402" data-hovercard-type="pull_request" data-hovercard-url="/Shopify/bootsnap/pull/402/hovercard" href="https://github.com/Shopify/bootsnap/pull/402">#402 Ref: https://bugs.ruby-lang.org/issues/10222 Ref: ruby/ruby@5754f15 Ref: ruby/ruby@b6d3927 Up to Ruby 2.3, `require` would resolve symlinks, but `require_relative` wouldn't: ```ruby require 'fileutils' FileUtils.mkdir_p("realpath") File.write("realpath/a.rb", "p :a_loaded") File.symlink("realpath", "symlink") rescue nil $LOAD_PATH.unshift(File.realpath(__dir__) + "/symlink") require "a.rb" # load symlink/a.rb in 2.3 and older, load realpath/a.rb on 2.4 and newer require_relative "realpath/a.rb" # noop on 2.4+ ``` This would easily cause double loading issue when `require` and `require_relative` were mixed, but was fixed in 2.4 (https://bugs.ruby-lang.org/issues/10222). The problem is that `Bootsnap` kinda negated this fix, because `realpath()` wouldn't be applied to absolute paths: ```ruby require 'fileutils' FileUtils.mkdir_p("realpath") File.write("realpath/a.rb", "p :a_loaded") File.symlink("realpath", "symlink") rescue nil $LOAD_PATH.unshift(File.realpath(__dir__) + "/symlink") require File.expand_path("symlink/a.rb") # load symlink/a.rb in 3.0 and older, load realpath/a.rb on 3.1 and newer require_relative "realpath/a.rb" # noop on 3.1+ ``` And for performance reasons, Bootsnap tried really hard not to call `realpath`, as it's a syscall, instead it used `expand_path`, which is entirely in use space and doesn't reach to the file system. So if you had a `symlink` in `$LOAD_PATH`, `bootcsnap` would perpetuate this bug, which led to the addition of #136. This was ultimately fixed in Ruby 3.1 (https://bugs.ruby-lang.org/issues/17885), now `realpath` is applied even on absolute paths. While `realpath` is indeed expensive, I think the performance impact is ok if we only call it for `$LOAD_PATH` members, rather than for all requirable files. So if you have X gems, it's going to be more or less X `realpath` calls. It would stay a problem if a gem actually contained symlinks and used `require_relative`, but it's quite the stretch, and with 3.1 now handling it, it's not worth keeping such workaround. See: #402

Commits

Commits on Feb 7, 2022

Drop Ruby 2.3 support.