ADDED   fish/completions/cross.fish
Index: fish/completions/cross.fish
==================================================================
--- fish/completions/cross.fish
+++ fish/completions/cross.fish
@@ -0,0 +1,27 @@
+function __fish_cross_none
+    if test (count (commandline -opc)) -gt 1
+        return 1
+    end
+end
+
+function __fish_cross_amiga
+    set -l cmd (commandline -opc)
+
+    if test (count $cmd) != 2 || test $cmd[2] != "amiga"
+        return 1
+    end
+end
+
+complete -c cross -x
+complete -c cross -n __fish_cross_none -x -a 3ds
+complete -c cross -n __fish_cross_none -x -a nds
+complete -c cross -n __fish_cross_none -x -a amiga
+complete -c cross -n __fish_cross_amiga -x -a m68k
+complete -c cross -n __fish_cross_amiga -x -a ppc
+complete -c cross -n __fish_cross_none -x -a ios
+complete -c cross -n __fish_cross_none -x -a iossim
+complete -c cross -n __fish_cross_none -x -a mingw
+complete -c cross -n __fish_cross_none -x -a morphos
+complete -c cross -n __fish_cross_none -x -a switch
+complete -c cross -n __fish_cross_none -x -a wii
+complete -c cross -n __fish_cross_none -x -a wii-u