Update fails with long file name

[Benjamin Fritz]

I'm not sure whether the problem is in Mercurial, or in hgsubversion, so
please let me know if this is a bad place to report the issue.

I cloned a SVN repository by creating a new (empty) hg repository, then
enabling the hgsubversion extension, and doing "hg pull" with the URL of my
SVN repository.

I used TortoiseSVN for all of the above, so I don't have the exact command
line.

The pull worked fine but the update step failed as follows:

E:\Project_Files\XXX-hg\Verification/XXX_config/Error_Config/XXXXXXXXX/XXXXXXXXXXXXXXXXXX0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678.csv

I tried ruling out hgsubversion as the culprit, by doing a normal "hg
clone" of that repository into a new location. I get the same error when
trying to update the new clone, which IIUC is a pure Hg repository now, so
I'm suspecting it's a Mercurial problem rather than hgsubversion, but I
have not even looked at the code of either project.

hg --version gives:

Mercurial Distributed SCM (version 3.2.1)
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