hg rm without removing the file?

[Marcin Kasperski]

I wrote:

> One can of course workaround by renaming file, hg rm --after
> it, and renaming it back, but it is problematic when the file
> is used by some processess (say, casus of pidfile, lockfile
> etc)

and you gave similar workaround:

> To get Hg to stop tracking a file, you need to 'hg rm' the
> file and add the filename into .hgignore. After the commit,
> you can 'hg cat' to retrieve the file.

which nevertheless does not solve the actual problem: there are 
cases when I do not want to remove the file which I want to stop 
tracking. Because, for instance, it is actively used by some 
running processess.