I'm hoping that WSL2 solves these problems and makes this question obsolete in the next 6 months or so, but in the meantime, I don't feel comfortable running bleeding edge or other preview releases of Windows on my primary laptop.
Sometimes, when I'm installing Ruby gems (bundle install or bundle install --path=vendor/bundle) inside of WSL, I get Permission denied errors when installing a gem with a native extension.
The most recent incarnation of this error was this:
Permission denied @ rb_file_s_rename - (./.gem.20191006-12131-11th7ub/byebug, /home/thomasowens/project/vendor/bundle/ruby/2.6.0/extensions/x86_64-linux/2.6.0-static/byebug-11.0.1/byebug)
To resolve it, I simply deleted /home/thomasowens/project/vendor/bundle/ruby/2.6.0/extensions/x86_64-linux/2.6.0-static/byebug-11.0.1/byebug, reran the bundle command, and it succeeded. Sometimes, I need to do this multiple times, but it usually works.
In the end, I can get all of the gems installed properly, but it's hard when setting up a new project and there are many gems with native extensions. Same when I'm introducing a new gem or updating a gem that causes the native dependencies to need to be updated.
I haven't found much about this issue, but I'm wondering if there is something that I can do to alleviate the pain of needing to run bundle install multiple times to get a project set up and running under WSL.
The problem that I'm experiencing may be related to Visual Studio Code's file watching. It is reflected in two GitHub issues against WSL - 1956 and 3395. Visual Studio Code has remote.WSL.fileWatcher.polling, which can be enabled which works around this issue. However, the documentation states that there is a performance impact for large workspaces and it may be necessary to also adjust the remote.WSL.fileWatcher.pollingInterval setting. WSL2 will resolve these issues.
Since enabling this flag, I haven't seen the error while working with VS Code running.
Now that WSL2 is out, I was able to disable this flag and the issue has not reappeared. It appears that if you can upgrade to WSL2, that may be a preferred solution. However, for anyone who hasn't yet upgraded or can't upgrade, toggling the remote.WSL.fileWatcher.polling and remote.WSL.fileWatcher.pollingInterval should be good.