GCC Doesn't build on Tier 3 Configuration, macOS 10.15.8 (Catalina)

[SenileFelineS]

Output of brew config

HOMEBREW_VERSION: 5.1.3-4-g8fbdcb7
ORIGIN: https://github.com/Homebrew/brew
HEAD: 8fbdcb73c88f1ca9b7e9168888578520c9137e6d
Last commit: 23 hours ago
Branch: main
Core tap HEAD: 65ccec5a832d68ba41f4d812a7d17b1864a2734e
Core tap last commit: 3 weeks ago
Core tap JSON: 01 Apr 16:02 UTC
Core cask tap HEAD: 113e83ac817ad796554c2f6635d3c679b4afea9a
Core cask tap last commit: 3 weeks ago
Core cask tap JSON: 01 Apr 16:02 UTC
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CASK_OPTS: []
HOMEBREW_DISPLAY: /private/tmp/com.apple.launchd.EAZFfCEgaW/org.xquartz:0
HOMEBREW_DOWNLOAD_CONCURRENCY: 16
HOMEBREW_FORBID_PACKAGES_FROM_PATHS: set
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_SORBET_RUNTIME: set
Homebrew Ruby: 4.0.2 => /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/4.0.2_1/bin/ruby
CPU: octa-core 64-bit ivybridge
Clang: 12.0.0 build 1200
Git: 2.24.3 => /Applications/Xcode.app/Contents/Developer/usr/bin/git
Curl: 7.64.1 => /usr/bin/curl
macOS: 10.15.8-x86_64
CLT: 12.4.0.0.1.1610135815
Xcode: 12.4

Output of brew doctor

Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

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:
  python@3.13

Warning: You are using macOS 10.15.
We (and Apple) do not provide support for this old version.
You may have better luck with MacPorts which supports older versions of macOS:
  https://www.macports.org

This is a Tier 3 configuration:
  https://docs.brew.sh/Support-Tiers#tier-3
You can report issues with Tier 3 configurations to Homebrew/* repositories!
Read the above document before opening any issues or PRs.

Description of issue

If I shouldn't post this here...my apologies.

I'm trying to build gcc and I get the follow error:

==> ../configure --prefix=/usr/local/opt/gcc --libdir=/usr/local/opt/gcc/lib/gcc/current --disable-nls --enable-che
==> gmake BOOT_LDFLAGS=-Wl,-headerpad_max_install_names
Last 15 lines from /Users/guestadmin/Library/Logs/Homebrew/gcc/02.gmake.log:
checking for exp10 in -lm... no
checking for exp10f in -lm... no
checking for exp10l in -lm... no
checking for signbit in -lm... no
checking for signbitf in -lm... no
checking for signbitl in -lm... no
config-host: creating ./config.status
config.status: creating gm2-libs-host.h
rm gcc.pod gfortran.pod
gmake[3]: Leaving directory '/private/tmp/gcc-20260401-58630-9fbazc/gcc-15.2.0/build/gcc'
gmake[2]: *** [Makefile:5115: all-stage2-gcc] Error 2
gmake[2]: Leaving directory '/private/tmp/gcc-20260401-58630-9fbazc/gcc-15.2.0/build'
gmake[1]: *** [Makefile:24740: stage2-bubble] Error 2
gmake[1]: Leaving directory '/private/tmp/gcc-20260401-58630-9fbazc/gcc-15.2.0/build'
gmake: *** [Makefile:1101: all] Error 2

Is there any way I can get gcc to build? If I should provide more information, please let me know.

Thank you!

Relevant casks

gcc