There is already a "fish" shell.
diff -ur bsd-games-2.17.orig/fish/Makefrag bsd-games-2.17/fish/Makefrag
--- bsd-games-2.17.orig/fish/Makefrag	1970-01-01 07:00:01.000000000 +0700
+++ bsd-games-2.17/fish/Makefrag	2020-08-06 19:18:43.204492847 +0700
@@ -31,7 +31,7 @@
 fish_all:	fish/fish fish/fish.instr fish/fish.6

 fish_install:	fish_all
-	$(INSTALL_BINARY) fish/fish $(INSTALL_PREFIX)$(GAMESDIR)/fish
+	$(INSTALL_BINARY) fish/fish $(INSTALL_PREFIX)$(GAMESDIR)/fish-game
	$(HIDE_GAME) fish
	$(INSTALL_DATA) fish/fish.instr $(INSTALL_PREFIX)$(FISH_INSTRFILE)
	$(INSTALL_MANUAL) fish/fish.6
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<tr><td><span title='2020-11-28 23:05:46 -0500'>2020-11-28</span></td><td><a href='/guix/commit/gnu/packages/loko.scm?id=40352788ded612d689cf414952f279532fab0375'>gnu: loko: Update to 0.7.0</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/loko.scm (loko-scheme): Update to 0.7.0

Signed-off-by: Kei Kebreau &lt;kkebreau@posteo.net&gt;
</span></span></td><td>Martin Becze</td></tr>
<tr><td><span title='2020-09-10 09:27:02 +0200'>2020-09-10</span></td><td><a href='/guix/commit/gnu/packages/loko.scm?id=cc6b1852e15f0c438a5f38bacb7cc8b1916121da'>gnu: Add loko-scheme.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/loko.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

Signed-off-by: Mathieu Othacehe &lt;othacehe@gnu.org&gt;
</span></span></td><td>Martin Becze</td></tr>