Hallo! Roland, you're CCed as the original expert; Jérémie you're CCed as the next expert. :-)
Text reproduced from <http://www.bddebian.com:8888/~hurd-web/open_issues/git-core-2/>: Running ``git checkout -f'' under GDB: error: git checkout-index: unable to create file gas/testsuite/gas/cris/string-1.s (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/i386/x86-64-sse-check.d (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/i386/x86-64-sse4_1.d (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/ppc/astest.d (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/tic6x/reloc-bad-4.s (File exists) warning: unable to unlink include/cgen: Operation not permitted fatal: cannot create directory at 'include/cgen': Operation not permitted Again: error: git checkout-index: unable to create file gas/config/te-vxworks.h (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/cris/string-1.s (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/d10v/warning-019.s (File exists) error: git checkout-index: unable to create file gas/testsuite/gas/i860/dual03.s (File exists) error: git checkout-index: unable to create file ld/testsuite/ld-mmix/sec-7a.s (File exists) warning: unable to unlink ld/testsuite/ld-powerpc: Operation not permitted fatal: cannot create directory at 'ld/testsuite/ld-powerpc': Operation not permitted And: <http://www.bddebian.com:8888/~hurd-web/open_issues/git_duplicated_content/> All these (very likely) have the same root cause: SA_RESTART restarting too much. With ``git checkout'', Git uses in progress.c a SIGALRM handler (`SA_RESTART`; invoked every second via `setitimer(ITIMER_REAL)`) to display status messages: ``x % already checked out''. To avoid the status update signals every second, in [git]/progress.c:start_progress_delay we can just return NULL (manually in GDB, for example), then both the ``error: git checkout-index'' and the duplicated content (see URL above) issues go away. I'm guessing that when returning from a SA_RESTART signal handler, too much of the ``syscall''s is being restarted. For example, if a file has already been created, the restarted creation attempt would fail: *File exists*. If data has been written, it might get written again (duplication issue). Then, there are cases where `unlink` apparently returns EINTR, which is not kosher either. Etc. Do we have problems with SA_RESTART vs. the atomicity of our syscall-alikes? Grüße, Thomas
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