How to recover a removed file in Mercurial (if at all)

You can see dangling commits with git log -g.

-g, --walk-reflogs
 Instead of walking the commit ancestry chain, walk reflog entries from
 the most recent one to older ones. 

So you could do this to find a particular string in a commit message that is dangling:

git log -g --grep=search_for_this

Alternatively, if you want to search the changes for a particular string, you could use the pickaxe search option, "-S":

git log -g -Ssearch_for_this
# this also works but may be slower, it only shows text-added results
git grep search_for_this $(git log -g --pretty=format:%h)

Git 1.7.4 will add the -G option, allowing you to pass -G<regexp> to find when a line containing <regexp> was moved, which -S cannot do. -S will only tell you when the total number of lines containing the string changed (i.e. adding/removing the string).

Finally, you could use gitk to visualise the dangling commits with:

gitk --all $(git log -g --pretty=format:%h)

And then use its search features to look for the misplaced file. All these work assuming the missing commit has not "expired" and been garbage collected, which may happen if it is dangling for 30 days and you expire reflogs or run a command that expires them.

Add the Mercurial Extension called purge. It is distributed by Mercurial.

This extension adds a “purge” command to “hg” that removes files not known to Mercurial. i.e. untracked Files. So your command would be,

hg purge

It is not enabled by default, maybe to avoid accidentally removing files that you forgot to add.

To install this extension, add this to your mercurial settings file (.hgrc on Unix, Mercurial.ini on Windows)

[extensions]
purge = 

To enable this extension temporarily you can use

hg purge --config extensions.purge=