+(test-assert "union-build collision first & last"
+ (let* ((guile (package-derivation %store %bootstrap-guile))
+ (fake (build-expression->derivation
+ %store "fake-guile"
+ '(begin
+ (use-modules (guix build utils))
+ (let ((out (assoc-ref %outputs "out")))
+ (mkdir-p (string-append out "/bin"))
+ (call-with-output-file (string-append out "/bin/guile")
+ (const #t))))
+ #:modules '((guix build utils))))
+ (builder (lambda (policy)
+ `(begin
+ (use-modules (guix build union)
+ (srfi srfi-1))
+ (union-build (assoc-ref %outputs "out")
+ (map cdr %build-inputs)
+ #:resolve-collision ,policy))))
+ (drv1
+ (build-expression->derivation %store "union-first"
+ (builder 'first)
+ #:inputs `(("guile" ,guile)
+ ("fake" ,fake))
+ #:modules '((guix build union))))
+ (drv2
+ (build-expression->derivation %store "union-last"
+ (builder 'last)
+ #:inputs `(("guile" ,guile)
+ ("fake" ,fake))
+ #:modules '((guix build union)))))
+ (and (build-derivations %store (list drv1 drv2))
+ (with-directory-excursion (derivation->output-path drv1)
+ (string=? (readlink "bin/guile")
+ (string-append (derivation->output-path guile)
+ "/bin/guile")))
+ (with-directory-excursion (derivation->output-path drv2)
+ (string=? (readlink "bin/guile")
+ (string-append (derivation->output-path fake)
+ "/bin/guile"))))))
+