Installing gems doesn't consider already installed gems

[alagos]

I'm having the following mise.toml file in my project

[tools]
ruby = "2.4"
node = "14"
python = "2"
"gem:mailcatcher" = "0.8.2" # last one to support Ruby 2.4

[env]
# flags to install Ruby 2.4 on Apple Silicon
RUBY_CFLAGS = "-Wno-error=implicit-function-declaration"
PKG_CONFIG_PATH = "/opt/homebrew/opt/openssl@1.1/lib/pkgconfig"
# Required by psych gem
RUBY_CONFIGURE_OPTS = "--with-libyaml-dir=$HOMEBREW_PREFIX/opt/libyaml"

[settings]
env_shell_expand = true

but the mailcatcher gem installation isn't working as it should because is trying to install a sqlite3 version uncompatible with ruby 2.4, not considering there's already a compatible sqlite3 version installed (from the Gemfile in the project).

❯ mise install --verbose
DEBUG ARGS: /opt/homebrew/bin/mise install --verbose
DEBUG [vfox] Getting metadata for yarn
DEBUG [vfox] Getting metadata for yarn
DEBUG config: ~/workspace/vwork/vworkapp/webapp/mise.toml
DEBUG config: ~/.tool-versions
DEBUG EnvResults { env: ["RUBY_CFLAGS", "PKG_CONFIG_PATH", "RUBY_CONFIGURE_OPTS"] }
INFO  gem:mailcatcher@0.8.2 [1/3] install
DEBUG $ gem install mailcatcher --version 0.8.2 --install-dir /Users/alter/.local/share/mise/installs/gem-mailcatcher/0.8.2/libexec
INFO  gem:mailcatcher@0.8.2 [1/3] Successfully installed daemons-1.4.1
INFO  gem:mailcatcher@0.8.2 [1/3] Building native extensions. This could take a while...
INFO  gem:mailcatcher@0.8.2 [1/3] Successfully installed eventmachine-1.0.9.1
INFO  gem:mailcatcher@0.8.2 [1/3] Successfully installed rack-1.6.13
INFO  gem:mailcatcher@0.8.2 [1/3] Building native extensions. This could take a while...
ERROR:  Error installing mailcatcher:
	sqlite3 requires Ruby version >= 2.7. The current ruby version is 2.4.10.364.
INFO  gem:mailcatcher@0.8.2 [1/3] Successfully installed thin-1.5.1
INFO  gem:mailcatcher@0.8.2 [1/3] Successfully installed skinny-0.2.4
INFO  gem:mailcatcher@0.8.2 [1/3] Successfully installed mini_portile2-2.8.9
ERROR gem failed
DEBUG [vfox] Getting metadata for yarn
DEBUG [vfox] Getting metadata for yarn
DEBUG config: ~/workspace/vwork/vworkapp/webapp/mise.toml
DEBUG config: ~/.tool-versions
DEBUG EnvResults { env: ["RUBY_CFLAGS", "PKG_CONFIG_PATH", "RUBY_CONFIGURE_OPTS"] }
Error:
   0: Failed to install gem:mailcatcher@0.8.2: gem exited with non-zero status: exit code 1

Location:
   src/toolset/toolset_install.rs:230

Version:
   2026.2.16 macos-arm64 (2026-02-18)

Backtrace omitted. Run with RUST_BACKTRACE=1 environment variable to display it.
Run with RUST_BACKTRACE=full to include source snippets.
❯ gem list|grep sqlite3
sqlite3 (1.3.13)
❯ which gem
/Users/alter/.local/share/mise/installs/ruby/2.4.10/bin/gem

then if I try manually (taken from the verbose output):

gem install mailcatcher --version 0.8.2 --install-dir /Users/alter/.local/share/mise/installs/gem-mailcatcher/0.8.2/libexec

fails by the same reason, but calling it without the --install-dir part, works without problems:

❯ gem install mailcatcher --version 0.8.2
Fetching mailcatcher-0.8.2.gem
Successfully installed mailcatcher-0.8.2
Parsing documentation for mailcatcher-0.8.2
Installing ri documentation for mailcatcher-0.8.2
Done installing documentation for mailcatcher after 0 seconds
1 gem installed

Not sure if that's intentional, like gems will work in isolation to the gems working for the current ruby installation.
Even if I add to the mise.toml file:

"gem:sqlite3" = "1.6.9" # last one to support Ruby 2.4

that isn't really making any difference by these same "isolation" reasons that I think are happening.
And why don't I just add the gem to the Gemfile of my project? that's because it conflicts with some other important gems for the Rails app I'm running, even the mailcatcher devs discourage to add it by the same reasons, so mise looked like the perfect tool to add it, but it doesn't really work as I would have expected 😞 .
Any idea how to deal with this?