Re: wip-ungrafting builds stuck

[Mark H Weaver]

Mathieu Othacehe <othacehe@gnu.org> writes:

>> Any idea what could be wrong, Mathieu?  What would you suggest to do
>> when investigating such issues?
>
> Yes I noticed it. The main problem here is that almost all workers are
> stuck building Rust.
>
> I see two actions here:
>
> 1. Understand why Rust is taking so long to build.

The attached patch, which I've been using on my private branch of Guix
for a long time and is fully tested, would significantly speed up the
Rust bootstrap.  I never submitted it because I wasn't sure it would be
of interest.

       Mark

>From cfe7ed9732e77eacf7f9e6b6db0d731b2f7d100e Mon Sep 17 00:00:00 2001
From: Mark H Weaver <mhw@netris.org>
Date: Sun, 19 Jul 2020 23:13:28 -0400
Subject: [PATCH] gnu: rust: Disable check phases of versions before 1.40.

This saves 49 hours of total build time on a Thinkpad X200.

* gnu/packages/rust.scm (rust-1.19)[arguments]: Add "#:tests? #f".
(rust-1.20, rust-1.26)[arguments]: Modify the custom 'check' phase to honor
the '#:tests?' argument.
(rust-1.40)[arguments]: Override '#:tests?' argument to be #t.
---
 gnu/packages/rust.scm | 40 ++++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/gnu/packages/rust.scm b/gnu/packages/rust.scm
index 3952a17908..2b9f26c204 100644
--- a/gnu/packages/rust.scm
+++ b/gnu/packages/rust.scm
@@ -236,6 +236,8 @@ safety and thread safety guarantees.")
     (arguments
      `(#:imported-modules ,%cargo-utils-modules ;for `generate-all-checksums'
        #:modules ((guix build utils) (ice-9 match) (guix build 
gnu-build-system))
+       #:tests? #f  ;Disable the test suite for early versions of rust to save
+                    ;compile time.
        #:phases
        (modify-phases %standard-phases
          (add-after 'unpack 'set-env
@@ -596,11 +598,16 @@ jemalloc = \"" jemalloc "/lib/libjemalloc_pic.a" "\"
                  (invoke "./x.py" "build")
                  (invoke "./x.py" "build" "src/tools/cargo")))
              (replace 'check
-               (lambda* _
-                 ;; Disable parallel execution to prevent EAGAIN errors when
-                 ;; running tests.
-                 (invoke "./x.py" "-j1" "test" "-vv")
-                 (invoke "./x.py" "-j1" "test" "src/tools/cargo")
+               (lambda* (#:key (tests? #t) #:allow-other-keys)
+                 (if tests?
+                     (let ((parallel-job-spec
+                            ;; Disable parallel execution to prevent EAGAIN
+                            ;; errors when running tests.
+                            "-j1"))
+                       (invoke "./x.py" parallel-job-spec "test" "-vv")
+                       (invoke "./x.py" parallel-job-spec "test"
+                               "src/tools/cargo"))
+                     (format #t "test suite not run~%"))
                  #t))
              (replace 'install
                (lambda* (#:key outputs #:allow-other-keys)
@@ -774,15 +781,16 @@ jemalloc = \"" jemalloc "/lib/libjemalloc_pic.a" "\"
              ;; binaryen was replaced with LLD project from LLVM
              (delete 'dont-build-native)
              (replace 'check
-               (lambda* _
-                 ;; Enable parallel execution.
-                 (let ((parallel-job-spec
-                        (string-append "-j" (number->string
-                                             (min 4
-                                                  (parallel-job-count))))))
-                   (invoke "./x.py" parallel-job-spec "test" "-vv")
-                   (invoke "./x.py" parallel-job-spec "test"
-                           "src/tools/cargo"))))
+               (lambda* (#:key (tests? #t) #:allow-other-keys)
+                 (if tests?
+                     (let ((parallel-job-spec
+                            ;; Enable parallel execution.
+                            (format #f "-j~a" (min 4 (parallel-job-count)))))
+                       (invoke "./x.py" parallel-job-spec "test" "-vv")
+                       (invoke "./x.py" parallel-job-spec "test"
+                               "src/tools/cargo"))
+                     (format #t "test suite not run~%"))
+                 #t))
              (replace 'remove-unsupported-tests
                (lambda* _
                  ;; Our ld-wrapper cannot process non-UTF8 bytes in 
LIBRARY_PATH.
@@ -1226,6 +1234,10 @@ move around."
        ;; which makes this workaround only necessary for this release.
        (cons* #:validate-runpath? #f
          (substitute-keyword-arguments (package-arguments base-rust)
+           ((#:tests? _ #t)
+            ;; Enable the test suite, which was disabled for earlier versions
+            ;; of rust to save compile time.
+            #t)
            ((#:phases phases)
             `(modify-phases ,phases
                ;; We often need to patch tests with various Guix-specific 
paths.
-- 
2.31.1