brew upgrade for HEAD formulas fails with error: already installed

[jasonblewis]

brew upgrade formula on a formula that was initially installed with the --HEAD option fails with:

Error: formula-HEAD already installed

There is no clear way to upgrade a formula installed with --HEAD other than uninstalling and re-installing. Example:

jason@woodhouse:/usr/local/Library/Formula$ brew install --HEAD wol
==> Cloning https://github.com/kylef/wol.git
Cloning into /Users/jason/Library/Caches/Homebrew/wol--git...
remote: Counting objects: 13, done.
remote: Compressing objects: 100% (12/12), done.
remote: Total 13 (delta 2), reused 0 (delta 0)
Unpacking objects: 100% (13/13), done.
==> make
/usr/local/Cellar/wol/HEAD: 4 files, 24K, built in 16 seconds
jason@woodhouse:/usr/local/Library/Formula$ brew upgrade wol
Error: wol-HEAD already installed
jason@woodhouse:/usr/local/Library/Formula$ brew upgrade --HEAD wol
Error: wol-HEAD already installed
jason@woodhouse:/usr/local/Library/Formula$

Max Howell suggested that this should either be fixed or the error message improved and requested I open this ticket.

[mistydemeo]

The error has changed since specs landed, but it's actually odder now:

wget: stable 1.14, HEAD
http://www.gnu.org/software/wget/
/usr/local/Cellar/wget/HEAD (46 files, 2.1M) *

But:

brew upgrade wget
Error: wget-1.14 already installed

Which of course it isn't.

Ping @jacknagel

[jacknagel]

You can't upgrade a HEAD installation; it takes precedence over the stable version.

This error is generated in formula_installer.rb.

[jacknagel]

(But the error is misleading now that all specs are on a level playing field, yes.)

[jacknagel]

The issue with the error is that Formula#version is called, but the stable spec is active because --HEAD was not passed. I'm a little confused why this used to return HEAD in the first place without passing --HEAD, but I'm sure I'm missing something.

The correct way to get the installed version would be something like f.linked_keg.version, which doesn't exist in core yet, but does in my versions overhaul.

[jacknagel]

I have a fix for the error message at the tip of my specs branch: https://github.com/jacknagel/homebrew/tree/specs

It depends on the other work in that branch.

It doesn't address the original issue here, but at least the weirdness that Misty reported should be resolved.

[jacknagel]

Working my way towards a resolution on this one; (hopefully) fixed a couple other bugs in upgrade.

[pepijndevos]

Any news on this? There is still no good way to update --HEAD builds.

[zen0wu]

Any progress? It's kind of surprising that homebrew cannot upgrade HEAD formula

[MikeMcQuaid]

We'll tell you when there's any progress here. We'd welcome patches from anyone else who wants to try though.

[mblair]

In the meantime, to upgrade a HEAD formula, just brew reinstall --HEAD [formula].

[sjackman]

As a workaround hack, could brew upgrade --HEAD formula be a synonym for brew reinstall --HEAD formula?

[FlorianFranzen]

Are you planing to give brew the ability to mark --HEAD versions outdated if there are new versions in the repository the code came from?