(address . guix-patches@gnu.org)(name . Ludovic Courtès)(address . ludo@gnu.org)
ff2861a715c9988e15794bc46bf71736c17fbebc.1686001563.git.ludo@gnu.org
With this change, commands such as 'guix build' or 'guix package' report
obvious package-level cycles upfront. Derivation-level cycles are not
detected.
* guix/packages.scm (&package-cyclic-dependency-error): New condition
type.
(package-transitive-supported-systems): Define 'visited', check it, and
parameterize it.
* guix/ui.scm (call-with-error-handling): Handle
'&package-cyclic-dependency-error'.
* tests/packages.scm ("package-transitive-supported-systems detects
cycles"): Add test.
---
guix/packages.scm | 41 ++++++++++++++++++++++++++++++-----------
guix/ui.scm | 9 +++++++++
tests/packages.scm | 17 +++++++++++++++++
3 files changed, 56 insertions(+), 11 deletions(-)
Hi!
At long last! This is a pretty basic cycle detection trick: it can only
detect package-level cycles and not more subtle things like that
in https://issues.guix.gnu.org/63331, but it’s also less expensive and
intrusive than something right into ‘package->derivation’.
Bonus: since ‘package-transitive-supported-systems’ is used when building
‘guix-package-cache.drv’, it would fail right during ‘guix pull’ instead
of eating up all the memory, as in https://issues.guix.gnu.org/63852.
Thoughts?
Ludo’.
Toggle diff (118 lines)
diff --git a/guix/packages.scm b/guix/packages.scm
index e26602d589..ba98bb0fb4 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -168,6 +168,9 @@ (define-module (guix packages)
package-error-invalid-license
&package-input-error
package-input-error?
+ &package-cyclic-dependency-error
+ package-cyclic-dependency-error?
+ package-error-dependency-cycle
package-error-invalid-input
&package-cross-build-system-error
package-cross-build-system-error?
@@ -806,6 +809,10 @@ (define-condition-type &package-input-error &package-error
package-input-error?
(input package-error-invalid-input))
+(define-condition-type &package-cyclic-dependency-error &package-error
+ package-cyclic-dependency-error?
+ (cycle package-error-dependency-cycle))
+
(define-condition-type &package-cross-build-system-error &package-error
package-cross-build-system-error?)
@@ -1317,17 +1324,29 @@ (define package-transitive-supported-systems
(let ()
(define (supported-systems-procedure system)
(define supported-systems
- (mlambdaq (package)
- (parameterize ((%current-system system))
- (fold (lambda (input systems)
- (match input
- ((label (? package? package) . _)
- (lset-intersection string=? systems
- (supported-systems package)))
- (_
- systems)))
- (package-supported-systems package)
- (bag-direct-inputs (package->bag package system #f))))))
+ ;; The VISITED parameter allows for cycle detection. This is a pretty
+ ;; strategic place to do that: most commands call it upfront, yet it's
+ ;; not on the hot path of 'package->derivation'. The downside is that
+ ;; only package-level cycles are detected.
+ (let ((visited (make-parameter (setq))))
+ (mlambdaq (package)
+ (when (set-contains? (visited) package)
+ (raise (condition
+ (&package-cyclic-dependency-error
+ (package package)
+ (cycle (set->list (visited)))))))
+
+ (parameterize ((visited (set-insert package (visited)))
+ (%current-system system))
+ (fold (lambda (input systems)
+ (match input
+ ((label (? package? package) . _)
+ (lset-intersection string=? systems
+ (supported-systems package)))
+ (_
+ systems)))
+ (package-supported-systems package)
+ (bag-direct-inputs (package->bag package system #f)))))))
supported-systems)
diff --git a/guix/ui.scm b/guix/ui.scm
index 7540e2194f..47a118364a 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -722,6 +722,15 @@ (define (call-with-error-handling thunk)
(leave (G_ "~a:~a:~a: package `~a' has an invalid input: ~s~%")
file line column
(package-full-name package) input)))
+ ((package-cyclic-dependency-error? c)
+ (let ((package (package-error-package c)))
+ (leave (package-location package)
+ (G_ "~a: dependency cycle detected:
+ ~a~{ -> ~a~}~%")
+ (package-full-name package)
+ (package-full-name package)
+ (map package-full-name
+ (package-error-dependency-cycle c)))))
((package-cross-build-system-error? c)
(let* ((package (package-error-package c))
(loc (package-location package))
diff --git a/tests/packages.scm b/tests/packages.scm
index 5e8eac99dc..2b7ab01f7d 100644
--- a/tests/packages.scm
+++ b/tests/packages.scm
@@ -368,6 +368,23 @@ (define %store
(package-transitive-supported-systems d)
(package-transitive-supported-systems e))))
+(test-equal "package-transitive-supported-systems detects cycles"
+ '("c" "a" "b" "c")
+ (letrec* ((a (dummy-package "a"
+ (build-system trivial-build-system)
+ (native-inputs (list c))))
+ (b (dummy-package "b"
+ (build-system trivial-build-system)
+ (inputs (list a))))
+ (c (dummy-package "c"
+ (build-system trivial-build-system)
+ (inputs (list b)))))
+ (guard (c ((package-cyclic-dependency-error? c)
+ (map package-name
+ (cons (package-error-package c)
+ (package-error-dependency-cycle c)))))
+ (package-transitive-supported-systems c))))
+
(test-assert "package-development-inputs"
;; Note: Due to propagated inputs, 'package-development-inputs' returns a
;; couple more inputs, such as 'linux-libre-headers'.
base-commit: 940665301de4effd065d24c167f619286f2adf4c
--
2.40.1