Bootsnap LoadError for Prism

[bparanj]

Steps to reproduce

bug_report.rb:

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  gem "bootsnap"
end

ENV["BOOTSNAP_CACHE_DIR"] = "bootsnap_cache"
require "bootsnap/setup"

require "prism"

Expected behavior

It should load the prism gem that is now part of Ruby 3.3.0 standard library. Any environment other than development results in error.

Actual behavior

RAILS_ENV=test ruby bug.rb
Fetching gem metadata from https://rubygems.org/...
Resolving dependencies...
/home/ubuntu/.rvm/gems/ruby-3.3.0@r71/gems/bootsnap-1.17.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:29:in `require': cannot load such file -- prism/prism (LoadError)
	from /home/ubuntu/.rvm/rubies/ruby-3.3.0/lib/ruby/3.3.0/prism.rb:96:in `<main>'
	from /home/ubuntu/.rvm/rubies/ruby-3.3.0/lib/ruby/3.3.0/bundled_gems.rb:74:in `require'
	from /home/ubuntu/.rvm/rubies/ruby-3.3.0/lib/ruby/3.3.0/bundled_gems.rb:74:in `block (2 levels) in replace_require'
	from /home/ubuntu/.rvm/gems/ruby-3.3.0@r71/gems/bootsnap-1.17.0/lib/bootsnap/load_path_cache/core_ext/kernel_require.rb:32:in `require'
	from bug.rb:14:in `<main>'

System configuration

Bootsnap version: 1.17.0

Ruby version: ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-linux]

Rails version: Rails 7.1.2

[casperisfine]

Hum, there must be more to it because I can't repro on my machine:

$ ruby /tmp/foo.rb
Fetching gem metadata from https://rubygems.org/...
Resolving dependencies...
ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [arm64-darwin23]
Prism

[casperisfine]

nevermind, I missed the RAILS_ENV was important, I can now repro.

Thanks, I'll have a look later today or tomorrow.

[casperisfine]

Something is very weird, the prism.so is is loaded as a relative path:

$ DISABLE_BOOTSNAP=true RAILS_ENV=test ruby /tmp/foo.rb  | grep prism
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/node.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/node_ext.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/parse_result.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/parse_result/comments.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/visitor.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/parse_result/newlines.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/debug.rb
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism/pack.rb
prism/prism.so
/opt/rubies/3.3.0/lib/ruby/3.3.0/prism.rb

prism/prism.so

Also the .so simply isn't in the Ruby installation at all it seems:

$ find  /opt/rubies/3.3.0/lib/ruby/3.3.0/  -name prism.so

I suspect it's loaded with some kind of hack. I'll dig more, but I fear we might need a hack on our side too :/

FYI @kddnewton

[casperisfine]

void
Init_Prism(void)
{
    ruby_init_ext("prism/prism.so", Init_prism);
}

// Private API for statically linked extensions.
// Used with the ext/Setup file, the --with-setup and
// --with-static-linked-ext configuration option, etc.
void
ruby_init_ext(const char *name, void (*init)(void))
{
    st_table *inits_table;
    rb_vm_t *vm = GET_VM();

    if (feature_provided(vm, name, 0))
        return;

    inits_table = vm->static_ext_inits;
    if (!inits_table) {
        inits_table = st_init_strtable();
        vm->static_ext_inits = inits_table;
    }
    st_update(inits_table, (st_data_t)name, register_init_ext, (st_data_t)init);
}

So as I suspected, prism.so doesn't actually exist, Ruby simply pretend it does.

[casperisfine]

1.17.1 is out with the fix. Thanks for the detailed report.

[kddnewton]

@casperisfine anything you need from me on this? Looks like you solved it.

[casperisfine]

Yeah, I worked around it. This was mostly to let you know.

[kddnewton]

Sounds good thanks!