simplecov: Simplecov cannot generate a new coverage report because it does not skip writing already existing asset files.

Hi all,

I was able to generate a coverage/index.html the first time I ran rspec with simplecov. Each subsequent time, I have encountered an error where, when attempting to create the coverage/index.html file, simplecov gets an error that it is not allowed to open an asset file.

1: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1292:in `open' /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1292:in `initialize': Permission denied @ rb_sysopen - /home/chase/eic/coverage/assets/0.10.2/smoothness/images/ui-bg_glass_65_ffffff_1x400.png (Errno::EACCES)

What we believe to be happening is that simplecov is attempting to copy files from the gem kept in our nix/store directory and write them to the coverage/assets directory in the application. The first time writing was successful; however, simplecov does not appear to have the necessary logic to skip writing files that already exist.

Full trace below:

Traceback (most recent call last):
	26: from /nix/store/9gf3q3vzp3f25vvknqb8cf3d68wrfnq2-ruby2.5.5-simplecov-0.17.0/lib/ruby/gems/2.5.0/gems/simplecov-0.17.0/lib/simplecov/defaults.rb:29:in `block in <top (required)>'
	25: from /nix/store/9gf3q3vzp3f25vvknqb8cf3d68wrfnq2-ruby2.5.5-simplecov-0.17.0/lib/ruby/gems/2.5.0/gems/simplecov-0.17.0/lib/simplecov.rb:201:in `run_exit_tasks!'
	24: from /nix/store/9gf3q3vzp3f25vvknqb8cf3d68wrfnq2-ruby2.5.5-simplecov-0.17.0/lib/ruby/gems/2.5.0/gems/simplecov-0.17.0/lib/simplecov/configuration.rb:182:in `block in at_exit'
	23: from /nix/store/9gf3q3vzp3f25vvknqb8cf3d68wrfnq2-ruby2.5.5-simplecov-0.17.0/lib/ruby/gems/2.5.0/gems/simplecov-0.17.0/lib/simplecov/result.rb:48:in `format!'
	22: from /nix/store/jws2anzzrgimgd4v95b05niw2j4q2rrg-ruby2.5.5-simplecov-html-0.10.2/lib/ruby/gems/2.5.0/gems/simplecov-html-0.10.2/lib/simplecov-html.rb:18:in `format'
	21: from /nix/store/jws2anzzrgimgd4v95b05niw2j4q2rrg-ruby2.5.5-simplecov-html-0.10.2/lib/ruby/gems/2.5.0/gems/simplecov-html-0.10.2/lib/simplecov-html.rb:18:in `each'
	20: from /nix/store/jws2anzzrgimgd4v95b05niw2j4q2rrg-ruby2.5.5-simplecov-html-0.10.2/lib/ruby/gems/2.5.0/gems/simplecov-html-0.10.2/lib/simplecov-html.rb:19:in `block in format'
	19: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:392:in `cp_r'
	18: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1461:in `fu_each_src_dest'
	17: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1477:in `fu_each_src_dest0'
	16: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1463:in `block in fu_each_src_dest'
	15: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:393:in `block in cp_r'
	14: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:415:in `copy_entry'
	13: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1392:in `wrap_traverse'
	12: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1392:in `each'
	11: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1393:in `block in wrap_traverse'
	10: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1392:in `wrap_traverse'
	 9: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1392:in `each'
	 8: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1393:in `block in wrap_traverse'
	 7: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1390:in `wrap_traverse'
	 6: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:418:in `block in copy_entry'
	 5: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1259:in `copy'
	 4: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1291:in `copy_file'
	 3: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1291:in `open'
	 2: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1292:in `block in copy_file'
	 1: from /nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1292:in `open'
/nix/store/fnmw699zb2pk8gn38ic99vx9ax53n9g6-ruby-2.5.5/lib/ruby/2.5.0/fileutils.rb:1292:in `initialize': Permission denied @ rb_sysopen - /home/chase/eic/coverage/assets/0.10.2/smoothness/images/ui-bg_glass_65_ffffff_1x400.png (Errno::EACCES)

I am using RSpec for tests and I run my tests using the following command nix-shell --run "rspec"

I am requiring and staring SimpleCov in my spec_helper.rb as seen below. Additionally, I have been able to successfully run simplecov once before, so I do not think this is the issue.

require 'simplecov'
SimpleCov.start 'rails'

Software Versions

Ruby 2.5.5p157 (2019-03-15) [x86_64-linux]
Rails v5.1.6
Simplecov (0.17.0)
Simplecov-html (0.10.2)

Please let me know if you have any questions or if I can provide any additional information and I’ll be happy to help.

Best, Chase

About this issue

Original URL
State: open
Created 5 years ago
Comments: 15

Most upvoted comments

When using Nix all the gems are stored read-only in /nix/store.

As you can see simplecov-html does a simple FileUtils.cp_r which preserves rights.

I would propose that the fix would be to chmod the files, e.g. 644?

felixscheinost on Mar 27, 2020

I’m a NixOS user too, and I’ve worked around this by adding the following to test_helper.rb:

require 'simplecov'
Pathname.new(__FILE__).join('..','..','coverage').tap do |cov|
  # clear old coverage results
  FileUtils.rm_rf cov if cov.exist?
end
SimpleCov.start('rails')

But if simplecov skipped rewriting the assets, that would be great!

emptyflask on Jul 8, 2020

Hey,

thanks to feedback here I thought about it some more and theoretically I guess we could:

read the files and just write them as new files to avoid this problem (as they should have no different rights set then)
we could catch the errors and warn but continue, that seems incredibly specific and probably not good though

As there seem to be a bit more people running into this than I expected I might try to provide a fix with higher priority, but no promises time is a bit volatile these days 😃

PragTob on Jul 19, 2020

@slinkp maybe 🤷

Couldn’t do it like this because it deletes the whole path. People might (accidentally) throw files in there and we can’t just delete them all.

Could we delete all the files we’re gonna copy over? Probably. Next thing I know maybe for some reason under some OS we don’t have the right to create files there… and then that case starts failing all of a sudden.

So, I’m not very inclined to include it into default. Asset inlining and/or having hashes build style at the end of the assets would be the proper solutions I think. For the time being people can implement this workaround.

Reopening to know/remember it’d be nice to fix these.

PragTob on Jul 16, 2020