Incremental upgrade fails on Wheezy due to tar vs. FAT filename case matching
Originally created by @intrigeri on #7025 (Redmine)
On Wheezy, I failed to applied an incremental upgrade: when trying to
extract the system tarball, tar dies with something like exithelp.cfg: Cannot open: File exists". On the filesystem, there is
EXITHELP.CFG, but the IUK apparently ships
exithelp.cfg@, and apparently tar fails to
detect that these are the same file on FAT32, and does not do the right
thing.
Moving EXITHELP.CFG
out of the way on the filesystem allowed me to
successfully complete the upgrade.