Puppet module upgrade fails - permission denied # rb_file_s_rename - ruby

Question

In my modules directory I have some modules from Puppet Forge, among others e.g. puppetlabs/stdlib.
I tried the module upgrade with the following command:
puppet module --modulepath . upgrade puppetlabs-stdlib --ignore-changes.
But I received the following error message:
Error: Permission denied # rb_file_s_rename - (/home/pk/.puppet/cache/puppet-module/cache/tmp20220620-5150-1b9vqt0/puppetlabs-stdlib-5.2.0, /home/pk/.puppet/cache/puppet-module/cache/puppetlabs-stdlib20220620-5150-1be31tk)
What could be the reason for the error and how can I fix it?
Detailed: Commands and terminal output
$ puppet module --modulepath . upgrade puppetlabs-stdlib
/usr/lib/ruby/vendor_ruby/puppet/util.rb:50: warning: Insecure world writable dir /mnt/c in PATH, mode 040777
Notice: Preparing to upgrade 'puppetlabs-stdlib' ...
Notice: Found 'puppetlabs-stdlib' (v5.1.0) in /mnt/c/Users/pk/Puppet_Project/modules ...
Error: Could not upgrade module 'puppetlabs-stdlib' (v5.1.0 -> latest)
Installed module has had changes made locally
Use `puppet module upgrade --ignore-changes` to upgrade this module anyway
Why changes should have been made in the module puppetlabs-stdlib is not clear to me, maybe a converted line end or a changed encoding, the change should be discarded in any case.
$ puppet module --modulepath . upgrade puppetlabs-stdlib --ignore-changes
/usr/lib/ruby/vendor_ruby/puppet/util.rb:50: warning: Insecure world writable dir /mnt/c in PATH, mode 040777
Notice: Preparing to upgrade 'puppetlabs-stdlib' ...
Notice: Found 'puppetlabs-stdlib' (v5.1.0) in /mnt/c/Users/pk/Puppet_Project/modules ...
Notice: Downloading from https://forgeapi.puppet.com ...
Error: Permission denied # rb_file_s_rename - (/home/pk/.puppet/cache/puppet-module/cache/tmp20220620-5150-1b9vqt0/puppetlabs-stdlib-5.2.0, /home/pk/.puppet/cache/puppet-module/cache/puppetlabs-stdlib20220620-5150-1be31tk)
/usr/lib/ruby/2.5.0/fileutils.rb:471:in `rename'
/usr/lib/ruby/2.5.0/fileutils.rb:471:in `block in mv'
/usr/lib/ruby/2.5.0/fileutils.rb:1463:in `block in fu_each_src_dest'
/usr/lib/ruby/2.5.0/fileutils.rb:1479:in `fu_each_src_dest0'
/usr/lib/ruby/2.5.0/fileutils.rb:1461:in `fu_each_src_dest'
/usr/lib/ruby/2.5.0/fileutils.rb:460:in `mv'
/usr/lib/ruby/vendor_ruby/puppet/module_tool/applications/unpacker.rb:86:in `move_into'
/usr/lib/ruby/vendor_ruby/puppet/module_tool/applications/unpacker.rb:13:in `unpack'
/usr/lib/ruby/vendor_ruby/puppet/forge.rb:210:in `unpack'
/usr/lib/ruby/vendor_ruby/puppet/forge.rb:174:in `prepare'
/usr/lib/ruby/vendor_ruby/puppet/module_tool/applications/upgrader.rb:189:in `block in run'
/usr/lib/ruby/vendor_ruby/puppet/module_tool/applications/upgrader.rb:189:in `each'
/usr/lib/ruby/vendor_ruby/puppet/module_tool/applications/upgrader.rb:189:in `run'
/usr/lib/ruby/vendor_ruby/puppet/face/module/upgrade.rb:73:in `block (3 levels) in <top (required)>'
/usr/lib/ruby/vendor_ruby/puppet/interface/action.rb+eval[wrapper]:264:in `upgrade'
/usr/lib/ruby/vendor_ruby/puppet/application/face_base.rb:247:in `main'
/usr/lib/ruby/vendor_ruby/puppet/application.rb:383:in `run_command'
/usr/lib/ruby/vendor_ruby/puppet/application.rb:375:in `block in run'
/usr/lib/ruby/vendor_ruby/puppet/util.rb:665:in `exit_on_fail'
/usr/lib/ruby/vendor_ruby/puppet/application.rb:375:in `run'
/usr/lib/ruby/vendor_ruby/puppet/util/command_line.rb:137:in `run'
/usr/lib/ruby/vendor_ruby/puppet/util/command_line.rb:73:in `execute'
/usr/bin/puppet:5:in `<main>'
$ ll ~/.puppet/cache/puppet-module/cache/
total 0
drwxr-xr-x 1 pk pk 4096 Jun 20 12:24 ./
drwxr-xr-x 1 pk pk 4096 Jun 20 12:24 ../
You see, I am working with WSL on Windows.
I think that warning: Insecure world writable dir /mnt/c in PATH, mode 040777 should not cause the error Permission denied # rb_file_s_rename. Looking at the cache folder, my user has write permissions, how the permissions of the chache files are set I don't know exactly unfortunately.
Not all upgrades fail
I also upgraded the derdanne/nfs package in the same way, without any problems.
$ puppet module --modulepath . upgrade derdanne-nfs --ignore-changes
/usr/lib/ruby/vendor_ruby/puppet/util.rb:50: warning: Insecure world writable dir /mnt/c in PATH, mode 040777
Notice: Preparing to upgrade 'derdanne-nfs' ...
Notice: Found 'derdanne-nfs' (v2.1.2) in /mnt/c/Users/pk/Puppet_Project/modules ...
Notice: Downloading from https://forgeapi.puppet.com ...
Notice: Upgrading -- do not interrupt ...
/mnt/c/Users/pk/Puppet_Project/modules
└── derdanne-nfs (v2.1.2 -> v2.1.8)

Answer 1

The message "Installed module has had changes made locally" suggests that at some point a file or directory in the module structure has been changed by a local user, if that local user wasn't the owner of the home directory or the change was done by someone who was root or sudo then you're going to get these permissions problems.
I doubt checking "~/.puppet/cache/puppet-module/cache/" will help, your problem is likely to be buried way down under /mnt/c/Users/pk/Puppet_Project/modules/stdlib and there are a lot of files under there.
I would try the following;
Copy /mnt/c/Users/pk/Puppet_Project/modules/stdlib to some backup location as it's probably not possible to figure out what's been changed on this module and you may need to refer back to it.
Delete the module from the system, rm -rf /mnt/c/Users/pk/Puppet_Project/modules/stdlib.
Reinstall the original version to get you back to a reasonable state puppet module --modulepath . install puppetlabs-stdlib --version 5.1.0.
Then run your upgrade command puppet module --modulepath . upgrade puppetlabs-stdlib.
But it's worth being really careful about this, the current version of stdlib is 8.2.0 and a lot of modules haven't caught up with this version yet. If you go to that version you're likely to find other modules with a dependency of stdlib below version 8 so I'd probably run puppet module --modulepath . upgrade puppetlabs-stdlib --ignore-changes --version 7.1.0 as most modules on the forge have a version that'll be fine with version 7.