brew info gives error on upgraded pinned formula

[koallen]

This issue is previously opened at homebrew-core by my mistake (Homebrew/homebrew-core#4301). Reopening here at brew.

• Ran brew update and retried your prior step?
• Ran brew doctor, fixed as many issues as possible and retried your prior step?

Bug reports:

Previously, I pinned gcc since I don't wanna upgrade it. Later r is upgraded and that forced a upgrade to gcc (from 5.3.0 to 6.1.0). After that, I ran brew cleanup to clean up old versions of packages. Just now I was trying to run brew info gcc, and I get an error saying Error: /usr/local/Cellar/gcc/5.3.0 is not a directory. This is similar to Homebrew/legacy-homebrew#46044.

I have to manually do brew unpin gcc and brew pin gcc so that I can get the correct info.

Is there some logical error in handling brew info with pinned packages?

PS: The bug is reproduced by @ilovezfs in Homebrew/homebrew-core#4301.

[MikeMcQuaid]

Should be fixed, I believe, by #846