[llvm] [lit] Add an option to lit which ratelimits progressbar output. (PR #186479)

[Nick Begg via llvm-commits]

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@@ -261,7 +261,23 @@ def __init__(self, term, header, useETA=True):
             self.startTime = time.time()
         # self.update(0, '')
 
+        self.lastUpdateTime = 0
+        self.minOutputInterval = minOutputInterval
+        # the checks preceeding us should prevent getting here if output is redirected
+        # - we don't want to rate limit (ie drop) output to a file
+        assert sys.stdout.isatty()
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neek78 wrote:

No, this class is not instantiated at all in non-tty cases. This is just to confirm that, hence - assert (and the comment)

https://github.com/llvm/llvm-project/pull/186479