commit 9595a247a doesn't compile on Windows without reverting a small previous change

doc/bugs/commit_9595a247a_needs_a_fix_to_build_on_Windows.mdwn

@@ -0,0 +1,85 @@
+### Please describe the problem.
+
+Git-annex commit 9595a247a doesn't compile on Windows without a small patch.
+Commit [[!commit 6329997ac44691937f1d7fe6a71da3184237b13b]] introduces a change for `mingw32_HOST_OS`
+that is not needed (function pattern gains an extra _ parameter). I guess the change was a leftover
+from earlier testing.
+
+### What steps will reproduce the problem?
+
+`stack setup && stack build`
+
+### What version of git-annex are you using? On what operating system?
+
+[[!format sh """
+git-annex version: 8.20210804-g9595a247a
+build flags: Assistant Webapp Pairing TorrentParser Feeds Testsuite S3 WebDAV
+dependency versions: aws-0.22 bloomfilter-2.0.1.0 cryptonite-0.26 DAV-1.3.4 feed-1.3.0.1 ghc-8.8.4 http-client-0.6.4.1 persistent-sqlite-2.10.6.2 torrent-10000.1.1 uuid-1.3.13 yesod-1.6.1.0
+key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_224 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 BLAKE2B256E BLAKE2B256 BLAKE2B512E BLAKE2B512 BLAKE2B160E BLAKE2B160 BLAKE2B224E BLAKE2B224 BLAKE2B384E BLAKE2B384 BLAKE2BP512E BLAKE2BP512 BLAKE2S256E BLAKE2S256 BLAKE2S160E BLAKE2S160 BLAKE2S224E BLAKE2S224 BLAKE2SP256E BLAKE2SP256 BLAKE2SP224E BLAKE2SP224 SHA1E SHA1 MD5E MD5 WORM URL X*
+remote types: git gcrypt p2p S3 bup directory rsync web bittorrent webdav adb tahoe glacier ddar git-lfs httpalso borg hook external
+operating system: mingw32 x86_64
+supported repository versions: 8
+upgrade supported from repository versions: 2 3 4 5 6 7
+"""]]
+
+Windows 10 version 21H1 (build 19043.1165), 64 bit.
+
+### Please provide any additional information below.
+
+Relevant parts of the build log:
+
+[[!format sh """
+jkniiv@AINESIS MINGW64 /c/annx
+$ tail -n 25 /c/Projektit/git-annex.branchable.com/git-annex--BUILD-210902-9595a247a/stack.build.LOG~102
+[428 of 665] Compiling Remote.GitLFS
+[429 of 665] Compiling Remote.Bup
+[430 of 665] Compiling Assistant.Gpg
+[431 of 665] Compiling Annex.Environment
+[432 of 665] Compiling Annex.Init
+
+Annex\Init.hs:261:1: error:
+    * Couldn't match type `(Bool, [a0])' with `[String]'
+      Expected type: m (Bool, [String])
+        Actual type: p0 -> (Bool, (Bool, [a0]))
+    * The equation(s) for probeCrippledFileSystem' have four arguments,
+      but its type `RawFilePath
+                    -> Maybe (RawFilePath -> m ())
+                    -> Maybe (RawFilePath -> m ())
+                    -> m (Bool, [String])'
+      has only three
+    |
+261 | probeCrippledFileSystem' _ _ _ _ = return (True, [])
+
+    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+
+--  While building package git-annex-8.20210803 (scroll up to its section to see the error) using:
+      C:\Users\jkniiv\Projektit\git-annex.branchable.com\git-annex--BUILD-210902-9595a247a\.stack-work\dist\29cc6475\setup\setup --builddir=.stack-work\dist\29cc6475 build exe:git-annex --ghc-options " -fdiagnostics-color=always"
+    Process exited with code: ExitFailure 1
+
+# End of transcript.
+"""]]
+
+The change I made was a simple revertion, as follows:
+
+[[!format diff """
+diff --git a/Annex/Init.hs b/Annex/Init.hs
+index 30c4f9753..1193e0b24 100644
+--- a/Annex/Init.hs
++++ b/Annex/Init.hs
+@@ -258,7 +258,7 @@ probeCrippledFileSystem'
+        -> Maybe (RawFilePath -> m ())
+        -> m (Bool, [String])
+ #ifdef mingw32_HOST_OS
+-probeCrippledFileSystem' _ _ _ _ = return (True, [])
++probeCrippledFileSystem' _ _ _ = return (True, [])
+ #else
+ probeCrippledFileSystem' tmp freezecontent thawcontent = do
+        let f = tmp P.</> "gaprobe"
+"""]]
+
+This then compiled cleanly and completed the test suite ok.
+
+### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)
+
+Git Annex is great. It works quite nicely with my multi-gigabyte backup files (largest around 180GB) via the BLAKE2B160E backend :)