hg log shows nothing after upgrade.

[Matt Mackall]

On Tue, 2015-01-13 at 01:10 -0600, Rob Landley wrote:
> Last week I backed up my home partition and reinstalled from ubuntu
> 12.04 to 14.04, and now my old mercurial directories don't work. "hg
> log" shows nothing, hg identify says:
> 
>   warning: ignoring unknown working parent 382d5b9ff2d5!
>   000000000000+ tip"

It's not your upgrade. Nothing has changed in the repository format
since 1.7 (2010) and the latest Mercurial will happily and transparently
read formats back to 0.5 (the format the main hg repo happens to still
be in!). Your Ubuntu has 2.0.2, your new one had 2.8.2, all ancient news
now. No one's ever reported any issue like this on upgrade.

>From your error message, I can see you have a .hg/dirstate file. It
points to a hash. It also knows there are modifications. So far so good.

What's not good is that hash is unknown and you have no log entries.
What that suggests is that you don't have a .hg/store/00changelog.i
file.

-- 
Mathematics is the supreme nostalgia of our time.