Symbol's value as variable is void: package-recipe--working-tree

[DamienCassou]

While trying to install EVM (and more precisely Cask which is installed automatically by EVM's install script), I get:

In toplevel form:
package-recipe.el:67:1:Warning: `(rcp package-recipe)' is a malformed function
package-recipe.el:67:15:Warning: reference to free variable
    `package-recipe--working-tree'
package-recipe.el:69:28:Warning: reference to free variable `rcp'
package-recipe.el:71:1:Warning: `(rcp package-recipe)' is a malformed function
package-recipe.el:71:15:Warning: reference to free variable
    `package-recipe--upstream-url'
In end of data:
package-recipe.el:109:1:Warning: the function `cl-defmethod' is not known to
    be defined.
Wrote /home/travis/.emacs.d/.cask/24.3/bootstrap/package-build-20180324.2042/package-recipe.elc
Done (Total of 1 file compiled, 3 failed, 2 skipped)
Symbol's value as variable is void: package-recipe--working-tree
Cask could not be bootstrapped. Try again later, or report an issue at https://github.com/cask/cask/issues

This is most probably a Cask issue, but because I don't want Cask, I decided to report it here :-).

[sambrightman]

cask/cask#420 is long since fixed (I also don't think EVM installs Cask - the "install script" is an example, which you are free to change if you don't want Cask).