Support packslip sources for vfox backend plugins (vfox-backend:)

[cprecioso]

Since #12948, vfox plugins can be installed from signed packslip archives. We maintain two vfox backend plugins (wasp-lang/mise-ghcup and wasp-lang/mise-cabal) and would like to distribute them the same way, but backend plugins don't seem to be a supported case yet:

• mise plugins install vfox-backend:foo 'packslip:owner/repo#1.0.0' fails with packslip plugin sources require the vfox plugin type (src/cli/plugins/install.rs).
• In [plugins], "vfox-backend:foo" = "packslip:owner/repo#1.0.0" resolves to PluginType::VfoxBackend (PluginType::from_plugin_entry), so the config path and the CLI path disagree.
• Using the vfox: prefix may happen to work, since the plugin type is re-detected from disk after install (hooks/backend_install.lua), but that's undocumented and untested. The docs and the archive contract (extensions.mise.plugin = "vfox") only describe tool plugins.

Request

1. Officially support packslip sources for vfox backend plugins, accepting the vfox-backend: prefix consistently in both the CLI and [plugins].
2. Document it in the backend plugin development docs, including what the archive should declare in extensions.mise.plugin.
3. Ideally, add e2e coverage with a backend plugin fixture.

Thanks!

[jdx]

Thanks, this is covered by #14727.

• vfox-backend: now accepts a packslip: source on both mise plugins install and in [plugins], so the two paths agree. asdf: and package: are still rejected.
• The archive contract is unchanged. A backend plugin's archive still declares extensions.mise.plugin = "vfox", because that names the archive format. mise recognizes a backend plugin by hooks/backend_install.lua. This is documented in the plugin publishing docs.
• The e2e only checks that the prefix is accepted, using the existing signed tool-plugin fixture. A signed backend fixture can't be produced locally, so a real one would have to come from a published release such as mise-ghcup.

AI-assisted — Tool: Claude Code; model: anthropic/claude-sonnet-5-5; version: 2.1.299.

[github-actions[bot]]

Implemented in #14727: feat(plugins): accept vfox-backend: for packslip plugin sources

[github-actions[bot]]

Fixed in v2026.10.17 by #14727. Update with mise self-update or see the install docs.