Fix Curry build & run

langs/curry.yaml

@@ -11,6 +11,8 @@ install:
   # We are installing from upstream because the Ubuntu 20.10 package
   # was broken (pakcs wouldn't start up due to swi-prolog being bumped
   # from 7.x to 8.x, causing a ZIP decoding error).
+  apt:
+    - swi-prolog
   manual: |
     install -d "${pkg}/opt"
     install -d "${pkg}/usr/local/bin"
@@ -28,7 +30,7 @@ install:
     ln -s /opt/pakcs/src/pakcs "${pkg}/usr/local/bin/"
 
 repl: |
-  pakcs
+  SWIPL=swipl pakcs
 
 main: "main.curry"
 template: |
@@ -36,7 +38,7 @@ template: |
   main = putStrLn "Hello, world!"
 
 run: |
-  pakcs :load main.curry :eval main
+  SWIPL=swipl pakcs :load main.curry :eval main
 
 scope:
   code: |