I'm not sure what changed, but it now doesn't work for me without
the "Start in" field being set.
Source: "bindistprep\ghc-@ProjectVersion@\*"; DestDir: "{app}"; Flags: recursesubdirs
[Icons]
Source: "bindistprep\ghc-@ProjectVersion@\*"; DestDir: "{app}"; Flags: recursesubdirs
[Icons]
-Name: "{group}\@ProjectVersion@\GHCi"; Filename: "{app}\bin\ghci.exe"
+Name: "{group}\@ProjectVersion@\GHCi"; Filename: "{app}\bin\ghci.exe"; WorkingDir: "{app}\bin"
Name: "{group}\@ProjectVersion@\GHC Documentation"; Filename: "{app}\doc\html\index.html"
Name: "{group}\@ProjectVersion@\GHC Library Documentation"; Filename: "{app}\doc\html\libraries\index.html"
Name: "{group}\@ProjectVersion@\GHC Flag Reference"; Filename: "{app}\doc\html\users_guide\flag-reference.html"
Name: "{group}\@ProjectVersion@\GHC Documentation"; Filename: "{app}\doc\html\index.html"
Name: "{group}\@ProjectVersion@\GHC Library Documentation"; Filename: "{app}\doc\html\libraries\index.html"
Name: "{group}\@ProjectVersion@\GHC Flag Reference"; Filename: "{app}\doc\html\users_guide\flag-reference.html"