diff --git a/doc/bugs/git-annex_does_not_build_reproducibly_from_readdir_order/comment_1_33571f940f88ebb3ff9cf08ef58364fb._comment b/doc/bugs/git-annex_does_not_build_reproducibly_from_readdir_order/comment_1_33571f940f88ebb3ff9cf08ef58364fb._comment
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+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 1"""
+ date="2020-06-30T14:10:23Z"
+ content="""
+ghc builds with concurrency enabled by default, which is bad for
+reproducibility. Passing -j1 may help.
+
+<https://gitlab.haskell.org/ghc/ghc/-/issues/4012>
+
+As this is a compiler issue, there's really very little I can do about it.
+"""]]