Formula built, but is not symlinked into /usr/local | Error: invalid byte sequence in UTF-8

[upunkt]

Output of brew config

HOMEBREW_VERSION: 4.2.4
ORIGIN: https://github.com/Homebrew/brew
HEAD: 1c612baa096c69f2fcb221c74e6f5b9979efdcee
Last commit: 23 hours ago
Core tap JSON: 16 Jan 12:26 UTC
Core cask tap JSON: 16 Jan 12:26 UTC
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.xZ8KQNqarg/org.xquartz:0
HOMEBREW_MAKE_JOBS: 4
Homebrew Ruby: 3.1.4 => /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/bin/ruby
CPU: quad-core 64-bit broadwell
Clang: 14.0.0 build 1400
Git: 2.16.2 => /usr/local/bin/git
Curl: 8.1.2 => /usr/bin/curl
macOS: 12.7.2-x86_64
CLT: 14.2.0.0.1.1668646533
Xcode: N/A

Output of brew doctor

Warning: You have unlinked kegs in your Cellar.
Leaving kegs unlinked can lead to build-trouble and cause formulae that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  ca-certificates
Error: invalid byte sequence in UTF-8
Please report this issue:
  https://docs.brew.sh/Troubleshooting
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/pathname.rb:232:in `match?'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/pathname.rb:232:in `absolute?'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/pathname.rb:414:in `join'
/usr/local/Homebrew/Library/Homebrew/extend/pathname.rb:321:in `resolved_path_exists?'
/usr/local/Homebrew/Library/Homebrew/diagnostic.rb:321:in `block (2 levels) in check_for_broken_symlinks'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/pathname.rb:571:in `block in find'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/find.rb:49:in `block (2 levels) in find'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/find.rb:48:in `catch'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/find.rb:48:in `block in find'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/find.rb:43:in `each'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/find.rb:43:in `find'
/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/pathname.rb:571:in `find'
/usr/local/Homebrew/Library/Homebrew/diagnostic.rb:320:in `block in check_for_broken_symlinks'
/usr/local/Homebrew/Library/Homebrew/diagnostic.rb:317:in `each'
/usr/local/Homebrew/Library/Homebrew/diagnostic.rb:317:in `check_for_broken_symlinks'
/usr/local/Homebrew/Library/Homebrew/cmd/doctor.rb:61:in `block in doctor'
/usr/local/Homebrew/Library/Homebrew/cmd/doctor.rb:54:in `each'
/usr/local/Homebrew/Library/Homebrew/cmd/doctor.rb:54:in `doctor'
/usr/local/Homebrew/Library/Homebrew/brew.rb:86:in `<main>'

Description of issue

Hi,
I've been trying to install ngspice and first came across

Error: Cannot link ca-certificates
Another version is already linked: /usr/local/Cellar/ca-certificates/2022-04-26

So I tried
brew upgrade ca-certificates

which resulted in

==> Upgrading ca-certificates
  2022-04-26 -> 2023-12-12 
Error: invalid byte sequence in UTF-8

Since I could not resolve this after some search I uninstalled Homebrew and tried to reinstall. Now I get stuck at this same point. I did have a harddrive crash some months ago and I have the impression this could be related. Question is, how do I get rid of affected files so that it makes a clean install possible?

Any help much appreciated. Thanks.

[upunkt]

3 months later... no progress.
I've been trying to solve warnings, to no avail. Seems whatever I try to accomplish it all starts to get stuck with this

/usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/lib/ruby/3.1.0/pathname.rb:232:in `match?'

and the following lines, see above. $PATH seems to be ok, no strange symbols in it like mentioned in other threads I found while searching for a solution.

Maybe someone can hint me at least where to look for wrong encoding or even corruption?