fix: melos throws a null check operator used on null when version missing.

[bsutton]

Is there an existing issue for this?

• I have searched the existing issues.

Version

fork of 7.3.0

Description

running melos list throws

 melos list
Downloading packages... . 
No dependencies would change in `xxxx/git/melos`.
Building package executable... 
Built melos_workspace:melos_dev.
Resolving dependencies... 
Downloading packages... 
  _fe_analyzer_shared 85.0.0 (92.0.0 available)
  analyzer 7.6.0 (9.0.0 available)
  analyzer_plugin 0.13.4 (0.13.11 available)
  custom_lint 0.8.0 (0.8.1 available)
  custom_lint_builder 0.8.0 (0.8.1 available)
  custom_lint_core 0.8.0 (0.8.1 available)
  custom_lint_visitor 1.0.0+7.7.0 (1.0.0+8.4.0 available)
  dart_style 3.1.1 (3.1.3 available)
  lints 2.1.1 (6.0.0 available)
  matcher 0.12.17 (0.12.18 available)
  test 1.26.3 (1.28.0 available)
  test_api 0.7.7 (0.7.8 available)
  test_core 0.6.12 (0.6.14 available)
Got dependencies!
13 packages have newer versions incompatible with dependency constraints.
Try `dart pub outdated` for more information.
Unhandled exception:
Null check operator used on a null value
#0      ExecutableInstallation._loadVersion (package:cli_launcher/cli_launcher.dart:159:38)
#1      ExecutableInstallation.version (package:cli_launcher/cli_launcher.dart:106:38)
#2      launchExecutable (package:cli_launcher/cli_launcher.dart:423:59)
<asynchronous suspension>
#3      main (file:///xxxx/melos/bin/melos_dev.dart:13:3)
<asynchronous suspension>

Steps to reproduce

fork the melos repo.

activate the fork:

cd path/to/melos/fork
melos activate
ce path/to/some/melos workspace
melos list

Expected behavior

melos list, list the packages.

Screenshots

No response

Additional context and comments

melos activate
Resolving dependencies... 
Downloading packages... 
Got dependencies!
Resolving dependencies in `/xxxx/git/melos`... 
Downloading packages... 
Got dependencies in `/xxx/git/melos`.
Resolving dependencies in `/xxx/git/melos`... 
Downloading packages... 
Got dependencies in `/xxx/git/melos`.
Building package executable... 
Built melos:melos.
melos run activate
  └> dart pub global activate --source="path" . --executable="melos" --overwrite
     └> RUNNING

Resolving dependencies...
Downloading packages...
Got dependencies!
Package melos_workspace is currently active at path "/xxxx/git/melos".
Installed executable melos.
ERROR: Replaced melos previously installed from melos.

Activated melos_workspace 0.0.0 at path "/xxxx/git/melos".

The melos workspace:

name: melos_test
version: 0.1.0
environment:
  sdk: ">=3.10.0 <4.0.0"
dev_dependencies:
  melos: ^7.3.0
workspace:
  - packages/mailbox
  - packages/mailer
melos: 
  path: ../../melos/packages/melos

Other

• I'm interested in working on a PR for this.