Doh. 05acba3d0506ec370485ca005a6aed7b9456965f was a misfix.

.travis.yml

@@ -19,7 +19,7 @@ otp_release:
 #   - R15B failing with timeout
 
 script: 
-  - "make check"
+  - "[ ! -d deps/merl ] || make -C deps/merl && make check"
 
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   irc: "chat.freenode.net#erlydtl"