Conflict between Eclipse JGit and Cygwin HOME

[David Karr]

I've been running Cygwin on my Windows 10 laptop for quite a while.  I use
git in Eclipse and in the shell.

What I'm describing isn't really a bug with Cygwin, but it breaks because
of the interaction with Cygwin, and I'm trying to find out a reasonable way
to fix this.

Over the weekend, I upgraded Windows 10 from 1709 to 1809.  Somehow after
that I have messed up how git is used in Eclipse.

The Eclipse JGit framework figures out where my git config is by checking
things in the following order:

- 1. %HOME% if set,
- 2. %HOMEDRIVE%\%HOMEPATH%, if %HOMEDRIVE% is set,
- 3. %HOMESHARE% if set,
- 4. Java system property "user.home".

The HOMEDRIVE, HOMEPATH, and HOMESHARE variables are set by my work
infrastructure, and I appear to have no control over them. The resulting
%HOMEDRIVE%\%HOMEPATH% doesn't even exist.

The HOME variable is set by Cygwin, apparently.  It is set to
"/home/<myuid>".  I'm guessing that JGit looks at that and can't do
anything with it, so it goes down the list and doesn't find anything
useful. I end up with bad git config values.

The workaround I've figured out is a batch file that sets HOME to the
expected Windows HOME, and then executes its command-line parameters.  I
changed the target property in the Eclipse shortcut to add the full path to
this batch file at the front of the command line, and then I have to find
the eclipse.exe file and get the desktop icon from it.  I'll have to do
this every time I install a new Eclipse distribution.