deal with cabal unpack not preserving execute bit

Build/Mans.hs

@@ -38,7 +38,9 @@ buildMans = do
 		if (Just srcm > destm)
 			then do
 				r <- system $ unwords
-					[ "./Build/mdwn2man"
+					-- Run with per because in some
+					-- cases it may not be executable.
+					[ "perl", "./Build/mdwn2man"
 					, progName src
 					, "1"
 					, src

doc/bugs/__91__Patch__93___fix___34__mdwn2man__58___cannot_execute_-_...__34__.mdwn

@@ -36,3 +36,5 @@ OpenBSD current
 Cabal 3.4.0.0
 
 git-annex master (commit `4e5a27841`)
+
+> [[done]] --[[Joey]]

doc/bugs/__91__Patch__93___fix___34__mdwn2man__58___cannot_execute_-_...__34__/comment_1_cbfd460b55cc2b9df1a37936b71b881d._comment

@@ -0,0 +1,17 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 1"""
+ date="2021-02-08T18:20:31Z"
+ content="""
+Reproduced by running `cabal unpack git-annex`. While the tarball on
+hackage does have execute bits, somehow cabal is not preserving them.
+Applied your patch, thanks.
+
+Cabal's ability to install anything more than a command into PATH is very
+limited, and also there's not really a good way to install man pages
+in a user's home directory in a way that will make man find them (ie,
+there's probably one way or less per OS, and all different). 
+So it's best to use the Makefile (from a git clone of the repo)
+if you want to install git-annex in a more complete manner, 
+ie system wide or generating a package of its files.
+"""]]