How to do regression testing using Cvs
written by Gerard Patel
(Extracted from wine/documentation/bugreports)
A problem that can happen sometimes is 'it used to work
before, now it doesn't anymore...'. Here is a step by step
procedure to try to pinpoint when the problem occured. This is
NOT for casual users.
Get the 'full cvs' archive from winehq. This archive is
the cvs tree but with the tags controlling the versioning
system. It's a big file (> 40 meg) with a name like
wine-cvsdirs-<last update date> (it's more than 100mb
when uncompressed, you can't very well do this with
small, old computers or slow Internet connections).
untar it into a repository directory:
cd /home/gerard
tar -zxfcvs-dirs-2000-05-20.tar.gz
mv wine repository
extract a new destination directory. This directory must
not be in a subdirectory of the repository else
cvs will think it's part of the
repository and deny you an extraction in the repository:
cd /home/gerard
mv wine wine_current (-> this protects your current wine sandbox, if any)
export CVSROOT=/home/gerard/repository
cd /home/gerard
cvs -d $CVSROOT checkout wine
Note that it's not possible to do a checkout at a given
date; you always do the checkout for the last date where
the wine-cvsdirs-xxx snapshot was generated.
Note also that it is possible to do all this with a direct
Cvs connection, of course. The full cvs file method is less
painful for the winehq cvs server and probably a bit faster
if you don't have a very good net connection.
If you use Cvs directly from the winehq.com server, do not
forget to add to your .cvsrc file:
cvs -z 3
update -dPA
diff -u
you will have now in the ~/wine
directory an image of the cvs tree, on the client side.
Now update this image to the date you want:
cd /home/gerard/wine
cvs -d $CVSROOT update -D "1999-06-01 EDT"
The date format is YYYY-MM-DD HH:MM:SS.
Using the EDT date format ensure that you will be able to
extract patches in a way that will be compatible with the
wine-cvs archive : http://www.winehq.com/hypermail/wine-cvs
Many messages will inform you that more recent files have
been deleted to set back the client cvs tree to the date
you asked, for example:
cvs update: tsx11/ts_xf86dga2.c is no longer in the repository
cvs update is not limited to upgrade to
a newer version as I have believed for far too long :-(
Now proceed as for a normal update:
./configure
make depend && make
If any non-programmer reads this, the fastest method to get
at the point where the problem occured is to use a binary
search, that is, if the problem occured in 1999, start at
mid-year, then is the problem is already here, back to 1st
April, if not, to 1st October, and so on.
If you have lot of hard disk free space (a full compile takes
currently 400 Mb), copy the oldest known working version before
updating it, it will save time if you need to go back (it's
better to make distclean before going back in time, so you
have to make everything if you don't backup the older version)
When you have found the day where the problem happened, continue
the search using the wine-cvs archive (sorted by date) and a
more precise cvs update including hour, minute, second :
cvs -d $CVSROOT update -D "1999-06-01 15:17:25 EDT"
This will allow you to find easily the exact patch that did it.
If you find the patch that is the cause of the problem, you have
almost won; report about it on comp.emulators.windows.wine
or susbscribe to wine-devel and post it there. There is a chance that the author
will jump in to suggest a fix; or there is always the possibility
to look hard at the patch until it is coerced to reveal where is
the bug :-)