Disable iseq cache in Ruby 2.5 #257
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Won’t this turn on iseq cache for 2.5 only? As far as I understand the logic currently implemented. |
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@kaspth good catch. It should be reversed. |
There are many bugs in Ruby 2.5 related with iseq cache making it hard to use tracepoints with it. This means that debuggers and any gem that uses tracepoint don't play well with bootsnap when used with Ruby 2.5. Until those issues are fixed in Ruby 2.5 we are going to disabled iseq cache in the `bootsnap/setup` file.
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Fixed |
| @@ -24,12 +24,15 @@ | |||
| cache_dir = File.join(app_root, 'tmp', 'cache') | |||
| end | |||
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| ruby_version = Gem::Version.new(RUBY_VERSION) | |||
| iseq_cache_enabled = ruby_version < Gem::Version.new('2.5.0') || ruby_version >= Gem::Version.new('2.6.0') | |||
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Just for my own curiosity, why are these matchers more correct versus something like RUBY_VERSION !~ /\A2\.5/?
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In this case they are not, I was just following the same pattern other parts of the codebase was using.
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Really the issue is when we're using 2.5.x and also Rails 6+, right? Is there some simple way you can think of to cheaply check that without throwing away performance for apps that haven't updated either? |
No. Even without Rails 6, if you have iseq cache enable, debugging doesn't work well due to a bug where trace points are not fired when iseq cache is enabled. See #168 and related issues. |
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I just saw that they marked @XrXr's to backport to 2.5, that should fix our issue so I'll remove this code when Ruby 2.5.5 is released. |
Ref: #257 The fix was backported in 2.5.4, so we can restrict the range to 2.5.0...2.5.3.
There are many bugs in Ruby 2.5 related with iseq cache making it hard to use tracepoints with it. This means that debuggers and any gem that uses tracepoint don't play well with bootsnap when used with Ruby 2.5.
Until those issues are fixed in Ruby 2.5 we are going to disabled iseq cache in the
bootsnap/setupfile.Fixes rails/rails#35475.