[Bugfix:RainbowGrades] Add omit-dir-time flag to Make command

[ziesski]

rsync: [generator] failed to set times on "/var/local/submitty/courses/s24/sample/rainbow_grades/raw_data/seating": Oper\ ation not permitted (1)

Above error sometimes occur when user runs rainbowgrades from terminal and gui.
According to stackoverflow it can be fixed by
adding -O / --omit-dir-times to command line which will avoid trying to set modification times on directories.

[holzbh]

Is this issue seen using make pull_test? make push_test? Both? Does this only happen for raw_data/seating/? Is this happening only on your VM? Does the source have to contain directories when this failure happens, or can this happen if the source directory only has files?

If you're always seeing a (sub-)directory in these errors, what is the timestamp on those directories? Have you tried looking at the various times? ls -l, ls -lu, ls -ct (those may or may not give different times depending on the OS and filesystem) -- if any of them are an invalid time (or even something strange like 1969) that may be an issue.

I think you also mentioned filesystems (some online answers talk about NFS, sounds like a long shot but it's possible - you'd probably notice by doing the ls commands above). Filesystem seems very unlikely if you're seeing this in GUI mode as well, but for the sake of completeness, if you want to rule it out I'd check the output of mount for the partitions where the data lives, and wherever Rainbow Grades is running (which might be on something like /tmp which could be a different mount point). You can run mount -l on whichever server you're using and inside the terminal you're running the command from if you want to see what the file systems in question are.

-O shouldn't affect the file modification times, which might alleviate some of @bmcutler 's concern, but I agree with her that we should understand why this happens before altering the command. Especially if it's only in some of the targets.

[ziesski]

After discussion during meeting, I was not able to reproduce this error, I will come back once I encounter this issue. Marking it as draft for now.

[bmcutler]

This is not a good solution to add. Make should use timestamps in deciding what to rebuild for efficiency.
Unless I am mistaken, we are not doing anything weird/unusual that requires disabling this key feature of Make.
I'm closing this PR.

(If there is a real bug, we need a proper description/steps to reproduce first)