It is not really helpful when a `git fetch` fails with the message:
fatal: mmap failed: No error
In the particular instance encountered by a colleague of yours truly,
the Win32 error code was ERROR_COMMITMENT_LIMIT which means that the
page file is not big enough.
Let's make the message
fatal: mmap failed: File too large
instead, which is only marginally better, but which can be associated
with the appropriate work-around: setting `core.packedGitWindowSize` to
a relatively small value.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
938a45ebaf