Linux: can't postinstall gcc

[Josh-Cena]

Additional Info

• I am using Windows Subsystem for Linux

Output of brew config

$ brew config
HOMEBREW_VERSION: 4.2.2-4-g080e61f
ORIGIN: https://github.com/Homebrew/brew
HEAD: 080e61f9bc0aa36c246a5377e42657c75e04c9d3
Last commit: 13 minutes ago
Core tap JSON: 02 Jan 01:17 UTC
HOMEBREW_PREFIX: /home/linuxbrew/.linuxbrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 1
Homebrew Ruby: 3.1.4 => /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/vendor/portable-ruby/3.1.4/bin/ruby
CPU: single-core 64-bit broadwell
Clang: N/A
Git: 2.25.1 => /bin/git
Curl: 7.68.0 => /bin/curl
Kernel: Linux 5.15.0-1053-azure x86_64 GNU/Linux
OS: Ubuntu 20.04.6 LTS (focal)
Host glibc: 2.31
/usr/bin/gcc: 9.4.0
/usr/bin/ruby: N/A
glibc: 2.35_1
gcc@11: N/A
gcc: N/A
xorg: N/A

Output of brew doctor

$ brew doctor
Your system is ready to brew.

Description of issue

I'm trying to install gcc (first transitively because some other package depends on it, but it can be reproduced just by installing gcc itself too). Here is relevant info:

$ brew cleanup

$ brew --version
Homebrew 4.2.2-4-g080e61f

$ brew update
Already up-to-date.

$ brew install --debug gcc
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading glibc from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading [email protected] from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc from API
/usr/bin/env /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/shims/shared/git --version
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gmp from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading autoconf from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading m4 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading perl from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading berkeley-db@5 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gdbm from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading expat from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading libxcrypt from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading automake from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading libtool from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading isl from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading libmpc from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading mpfr from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading zstd from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading lz4 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading xz from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading cmake from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading openssl@3 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading ca-certificates from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading ncurses from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading pkg-config from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gpatch from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading zlib from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading binutils from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading bison from API
==> Downloading https://ghcr.io/v2/homebrew/core/gcc/manifests/13.2.0-2
Already downloaded: /home/joshcena/.cache/Homebrew/downloads/1d624841f5f550e4bbc04910c0cfb20b89d0fc7f90ab213cead29d1518479e2b--gcc-13.2.0-2.bottle_manifest.json
==> Fetching gcc
==> Downloading https://ghcr.io/v2/homebrew/core/gcc/blobs/sha256:28257893721f3b163e4364b0ae437dcfdf5e3fd22b8d6d703fa8e02821d0d
Already downloaded: /home/joshcena/.cache/Homebrew/downloads/b9f7349e3560b18d9a07e1f287e743c352211c1bdedceb97c283208c9e5ceb98--gcc--13.2.0.x86_64_linux.bottle.2.tar.gz
==> Pouring gcc--13.2.0.x86_64_linux.bottle.2.tar.gz
/usr/bin/env tar --extract --no-same-owner --file /home/joshcena/.cache/Homebrew/downloads/b9f7349e3560b18d9a07e1f287e743c352211c1bdedceb97c283208c9e5ceb98--gcc--13.2.0.x86_64_linux.bottle.2.tar.gz --directory /tmp/d20240102-131214-d4vo4h
/usr/bin/env cp -pR /tmp/d20240102-131214-d4vo4h/gcc/. /home/linuxbrew/.linuxbrew/Cellar/gcc
==> Downloading https://formulae.brew.sh/api/cask.jws.json
/usr/bin/env /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/shims/shared/curl --disable --cookie /dev/null --globoff --user-agent Linuxbrew/4.2.2-4-g080e61f\ \(Linux\;\ x86_64\ Ubuntu\ 20.04.6\ LTS\)\ curl/7.68.0 --header Accept-Language:\ en --fail --progress-bar --remote-time --output /home/joshcena/.cache/Homebrew/api/cask.jws.json --location --time-cond /home/joshcena/.cache/Homebrew/api/cask.jws.json --disable --cookie /dev/null --globoff --show-error --user-agent Linuxbrew/4.2.2-4-g080e61f\ \(Linux\;\ x86_64\ Ubuntu\ 20.04.6\ LTS\)\ curl/7.68.0 --header Accept-Language:\ en --fail --progress-bar --compressed --speed-limit 100 --speed-time 5 https://formulae.brew.sh/api/cask.jws.json
######################################################################################################################## 100.0%
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@12 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@11 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@10 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@9 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@8 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@7 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@6 from API
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/brew.rb (Formulary::FormulaAPILoader): loading gcc@5 from API
Killed
joshcena@Teacup:~$ /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/postinstall.rb:28:in `rescue in <main>': private method `puts' called for nil:NilClass (NoMethodError)
        from /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/postinstall.rb:14:in `<main>'
/home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/postinstall.rb:16:in `initialize': Connection refused - connect(2) for /tmp/homebrew20240102-131214-97xyc5/socket (Errno::ECONNREFUSED)
        from /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/postinstall.rb:16:in `open'
        from /home/linuxbrew/.linuxbrew/Homebrew/Library/Homebrew/postinstall.rb:16:in `<main>'

$ /usr/bin/cc --version
cc (Ubuntu 9.4.0-1ubuntu1~20.04.2) 9.4.0
Copyright (C) 2019 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ which gcc
/usr/bin/gcc

I have followed https://docs.brew.sh/Homebrew-on-Linux. My OS is OS: Ubuntu 20.04.6 LTS x86_64. I am not even sure which step it fails at; looks like it's the ECONNREFUSED but how do I know what it's trying to connect to?