on musl systems, bundler does not include the relevant `musl` native gem platform in the lock file

### Describe the problem as clearly as you can

The desired behavior is:

> Given I am on a linux musl system,
> And I depend on a gem that with native (precompiled) gems,
> And that gem ships a `-linux-musl` variant,
> When I `bundle lock`,
> The PLATFORMS section of my `Gemfile.lock` should include my `-linux-musl` platform,
> And I should bundle the `-linux-musl` variant of the gem's native package.

However, in some scenarios, the correct `*-linux-musl` platform is omitted by bundler, leading to either choosing a less-appropriate platform gem (scenario 1 below), or a non-resolvable lock file (scenario 3 below).

Please note that this issue is probably a blocker for general consumption of `musl`-specific native gems.

/cc @segiddins @deivid-rodriguez


### Did you try upgrading rubygems & bundler?

Yes, this behavior is present with Rubygems 3.5.5 and Bundler 2.5.5.


### Post steps to reproduce the problem

Here are three scenarios to explore this problem space. I'm running these commands using the `ruby:3.3-alpine` docker image, and deleting `Gemfile.lock` at the beginning of each scenario.

To summarize what you're about to see:

1. when bundling a gem with `linux` and `linux-musl` variants, bundler omits the correct platform from the lock file
2. when bundling a gem with `linux-gnu` and `linux-musl` variants, everything works as expected
3. but when combining scenario 2 with a second gem that publishes a `linux` variant, the problem re-emerges

Here we go.


#### 1. a gem that publishes `*-linux` and `*-linux-musl` native gem variants

Let's use `rcee_precompiled` v0.5.0 (see https://rubygems.org/gems/rcee_precompiled/versions), which publishes

- rcee_precompiled-0.5.0-x86_64-linux.gem
- rcee_precompiled-0.5.0-x86_64-linux-musl.gem

Gemfile:

``` ruby
# Gemfile
source "https://rubygems.org"
gem "rcee_precompiled", "0.5.0"
```

run `bundle lock` (or `bundle install`), and the lock file contains:

```
GEM
  remote: https://rubygems.org/
  specs:
    rcee_precompiled (0.5.0-aarch64-linux)
    rcee_precompiled (0.5.0-aarch64-linux-musl)
    rcee_precompiled (0.5.0-arm-linux)
    rcee_precompiled (0.5.0-arm-linux-musl)
    rcee_precompiled (0.5.0-arm64-darwin)
    rcee_precompiled (0.5.0-x86-linux)
    rcee_precompiled (0.5.0-x86-linux-musl)
    rcee_precompiled (0.5.0-x86_64-darwin)
    rcee_precompiled (0.5.0-x86_64-linux)

PLATFORMS
  aarch64-linux
  aarch64-linux-musl
  arm-linux
  arm-linux-musl
  arm64-darwin
  x86-linux
  x86-linux-musl
  x86_64-darwin
  x86_64-linux

DEPENDENCIES
  rcee_precompiled (= 0.5.0)

BUNDLED WITH
   2.5.5
```

**Note the absence of `x86_64-linux-musl` in the PLATFORMS section.**

If I run `bundle show --paths` I can see that it's incorrectly chosen the `*-linux` flavor:

```
# bundle show --paths
/usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.5.5
/usr/local/bundle/gems/rcee_precompiled-0.5.0-x86_64-linux
```

I can fix this by specifically adding the correct platform to the lock file:

```
bundle lock --add-platform x86_64-linux-musl
bundle install
```

then the `Gemfile.lock` contains `x86_64-linux-musl`:

```
PLATFORMS
  aarch64-linux
  aarch64-linux-musl
  arm-linux
  arm-linux-musl
  arm64-darwin
  x86-linux
  x86-linux-musl
  x86_64-darwin
  x86_64-linux
  x86_64-linux-musl
```

and I can see it's now choosing the correct `musl` native gem variant:

```
# bundle show --paths
/usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.5.5
/usr/local/bundle/gems/rcee_precompiled-0.5.0-x86_64-linux-musl
```


#### 2. a gem that publishes `*-linux-gnu` and `*-linux-musl` native gem variants

Now let's use `rcee_precompiled` v0.5.1 which switched from `*-linux` to `*-linux-gnu`, and publishes

- rcee_precompiled-0.5.0-x86_64-linux-gnu.gem
- rcee_precompiled-0.5.0-x86_64-linux-musl.gem

Gemfile:

``` ruby
# Gemfile
source "https://rubygems.org"
gem "rcee_precompiled", "0.5.1"
```

run `bundle lock` (or `bundle install`), and the lock file contains (in part):

```
PLATFORMS
  aarch64-linux-gnu
  aarch64-linux-musl
  arm-linux-gnu
  arm-linux-musl
  arm64-darwin
  x86-linux-gnu
  x86-linux-musl
  x86_64-darwin
  x86_64-linux-gnu
  x86_64-linux-musl
```

**Yay! This works.** I see `x86_64-linux-musl` in the PLATFORMS section and `bundle show --paths` tells me it's choosing the right variant.

Cool cool cool.

#### 3. but now add another gem that publishes a `*-linux` platform native gem

Let's add `nokogiri`:

``` ruby
# Gemfile
source "https://rubygems.org"
gem "rcee_precompiled", "0.5.1"
gem "nokogiri"
```

run `bundle lock` (or `bundle install`), and the lock file contains (in part):

```
PLATFORMS
  aarch64-linux
  aarch64-linux-gnu
  aarch64-linux-musl
  arm-linux
  arm-linux-gnu
  arm-linux-musl
  arm64-darwin
  x86-linux
  x86-linux-gnu
  x86-linux-musl
  x86_64-darwin
  x86_64-linux
  x86_64-linux-gnu
```

Note that `x86_64-linux-musl` is now missing again! And if I attempt to `bundle install` I get an error:

```
Could not find gems matching 'rcee_precompiled (= 0.5.1)' valid for all resolution platforms (aarch64-linux,
aarch64-linux-gnu, aarch64-linux-musl, arm-linux, arm-linux-gnu, arm-linux-musl, arm64-darwin, x86-linux,
x86-linux-gnu, x86-linux-musl, x86_64-darwin, x86_64-linux, x86_64-linux-gnu) in rubygems repository
https://rubygems.org/ or installed locally.
```

However if I go through the process of:

```
bundle lock --add-platform x86_64-linux-musl
bundle install
```

then bundler will include `x86_64-linux-musl` in the PLATFORMS section of the lock file:

```
PLATFORMS
  aarch64-linux
  aarch64-linux-gnu
  aarch64-linux-musl
  arm-linux
  arm-linux-gnu
  arm-linux-musl
  arm64-darwin
  x86-linux
  x86-linux-gnu
  x86-linux-musl
  x86_64-darwin
  x86_64-linux
  x86_64-linux-gnu
  x86_64-linux-musl
```


and will choose the correct variant again:

```
# bundle show --paths
/usr/local/lib/ruby/gems/3.3.0/gems/bundler-2.5.5
/usr/local/bundle/gems/nokogiri-1.16.0-x86_64-linux
/usr/local/lib/ruby/gems/3.3.0/gems/racc-1.7.3
/usr/local/bundle/gems/rcee_precompiled-0.5.1-x86_64-linux-musl
```


### What were you expecting to happen?

In scenarios 1 and 3, I expect

- `bundle lock` to add `x86_64-linux-musl` to the PLATFORMS section of the lock file
- `bundle install` to resolve to the `x86_64-linux-musl` native gem variant for `rcee_precompiled`


### What actually happened?

Scenarios 1 and 3 seem to confuse bundler, which omits the correct local platform, `x86_64-linux-musl`, from the lock file.


### If not included with the output of your command, run `bundle env` and paste the output below

---

At the end of scenario 3, this is what `bundle env` emits:

## Environment

```
Bundler       2.5.5
  Platforms   ruby, x86_64-linux-musl
Ruby          3.3.0p0 (2023-12-25 revision 5124f9ac7513eb590c37717337c430cb93caa151) [x86_64-linux-musl]
  Full Path   /usr/local/bin/ruby
  Config Dir  /usr/local/etc
RubyGems      3.5.5
  Gem Home    /usr/local/bundle
  Gem Path    /root/.local/share/gem/ruby/3.3.0:/usr/local/lib/ruby/gems/3.3.0:/usr/local/bundle
  User Home   /root
  User Path   /root/.local/share/gem/ruby/3.3.0
  Bin Dir     /usr/local/bundle/bin
Tools         
  Git         not installed
  RVM         not installed
  rbenv       not installed
  chruby      not installed
```

## Bundler Build Metadata

```
Built At          2024-01-18
Git SHA           2efa8cec93
Released Version  true
```

## Bundler settings

```
app_config
  Set via BUNDLE_APP_CONFIG: "/usr/local/bundle"
silence_root_warning
  Set via BUNDLE_SILENCE_ROOT_WARNING: true
```

## Gemfile

### Gemfile

```ruby
source "https://rubygems.org"
gem "rcee_precompiled", "0.5.1"
gem "nokogiri"
```

### Gemfile.lock

```
GEM
  remote: https://rubygems.org/
  specs:
    nokogiri (1.16.0-aarch64-linux)
      racc (~> 1.4)
    nokogiri (1.16.0-arm-linux)
      racc (~> 1.4)
    nokogiri (1.16.0-arm64-darwin)
      racc (~> 1.4)
    nokogiri (1.16.0-x86-linux)
      racc (~> 1.4)
    nokogiri (1.16.0-x86_64-darwin)
      racc (~> 1.4)
    nokogiri (1.16.0-x86_64-linux)
      racc (~> 1.4)
    racc (1.7.3)
    rcee_precompiled (0.5.1-aarch64-linux-gnu)
    rcee_precompiled (0.5.1-aarch64-linux-musl)
    rcee_precompiled (0.5.1-arm-linux-gnu)
    rcee_precompiled (0.5.1-arm-linux-musl)
    rcee_precompiled (0.5.1-arm64-darwin)
    rcee_precompiled (0.5.1-x86-linux-gnu)
    rcee_precompiled (0.5.1-x86-linux-musl)
    rcee_precompiled (0.5.1-x86_64-darwin)
    rcee_precompiled (0.5.1-x86_64-linux-gnu)
    rcee_precompiled (0.5.1-x86_64-linux-musl)

PLATFORMS
  aarch64-linux
  aarch64-linux-gnu
  aarch64-linux-musl
  arm-linux
  arm-linux-gnu
  arm-linux-musl
  arm64-darwin
  x86-linux
  x86-linux-gnu
  x86-linux-musl
  x86_64-darwin
  x86_64-linux
  x86_64-linux-gnu
  x86_64-linux-musl

DEPENDENCIES
  nokogiri
  rcee_precompiled (= 0.5.1)

BUNDLED WITH
   2.5.5
```


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Uh oh!

Uh oh!

on musl systems, bundler does not include the relevant `musl` native gem platform in the lock file #7432

Describe the problem as clearly as you can

Did you try upgrading rubygems & bundler?

Post steps to reproduce the problem

1. a gem that publishes `-linux` and `-linux-musl` native gem variants

2. a gem that publishes `-linux-gnu` and `-linux-musl` native gem variants

3. but now add another gem that publishes a `*-linux` platform native gem

What were you expecting to happen?

What actually happened?

If not included with the output of your command, run `bundle env` and paste the output below

Environment

Bundler Build Metadata

Bundler settings

Gemfile

Gemfile

Gemfile.lock

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Uh oh!

on musl systems, bundler does not include the relevant musl native gem platform in the lock file #7432

Description

Describe the problem as clearly as you can

Did you try upgrading rubygems & bundler?

Post steps to reproduce the problem

1. a gem that publishes *-linux and *-linux-musl native gem variants

2. a gem that publishes *-linux-gnu and *-linux-musl native gem variants

3. but now add another gem that publishes a *-linux platform native gem

What were you expecting to happen?

What actually happened?

If not included with the output of your command, run bundle env and paste the output below

Environment

Bundler Build Metadata

Bundler settings

Gemfile

Gemfile

Gemfile.lock

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions

on musl systems, bundler does not include the relevant `musl` native gem platform in the lock file #7432

1. a gem that publishes `-linux` and `-linux-musl` native gem variants

2. a gem that publishes `-linux-gnu` and `-linux-musl` native gem variants

3. but now add another gem that publishes a `*-linux` platform native gem

If not included with the output of your command, run `bundle env` and paste the output below