ui: 'load*' accepts /dev/fd/N files pointing to a pipe.

This allows users to write Bash commands like:

  guix time-machine -C <(echo %default-channels) -- ...

or:

  guix build -m <(echo '(specifications->manifest (list "guile"))')

Previously, on GNU/Linux, they would fail with:

  error: failed to load '/dev/fd/63': No such file or directory

* guix/ui.scm (try-canonicalize-path): New procedure.
(load*): Use it.
* tests/guix-build.sh: Test 'guix build -m' with a /dev/fd/N file.
This commit is contained in:
Ludovic Courtès 2023-08-11 17:20:06 +02:00 committed by Ludovic Courtès
parent 9896b37ac5
commit 3363ff1867
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GPG key ID: 090B11993D9AEBB5
2 changed files with 23 additions and 2 deletions

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@ -200,6 +200,20 @@ (define-syntax-rule (without-compiler-optimizations exp)
(parameterize (((@ (system base compile) default-optimization-level) 1))
exp))
(define (try-canonicalize-path file)
"Like 'canonicalize-path', but return FILE as-is if 'canonicalize-path'
throws.
This is necessary for corner cases where 'canonicalize-path' fails. One
example is on Linux when a /dev/fd/N file denotes a pipe, represented as a
symlink to a non-existent file like 'pipe:[1234]', as in this example:
sh -c 'stat $(readlink -f /dev/fd/1)' | cat"
(catch 'system-error
(lambda ()
(canonicalize-path file))
(const file)))
(define* (load* file user-module
#:key (on-error 'nothing-special))
"Load the user provided Scheme source code FILE."
@ -230,7 +244,7 @@ (define tag
;; 'primitive-load', so that FILE is compiled, which then allows
;; us to provide better error reporting with source line numbers.
(without-compiler-optimizations
(load (canonicalize-path file))))
(load (try-canonicalize-path file))))
(const #f))))))
(lambda _
;; XXX: Errors are reported from the pre-unwind handler below, but

View file

@ -1,5 +1,5 @@
# GNU Guix --- Functional package management for GNU
# Copyright © 2012-2014, 2016-2022 Ludovic Courtès <ludo@gnu.org>
# Copyright © 2012-2014, 2016-2023 Ludovic Courtès <ludo@gnu.org>
# Copyright © 2020 Marius Bakke <mbakke@fastmail.com>
# Copyright © 2021 Chris Marusich <cmmarusich@gmail.com>
#
@ -397,6 +397,13 @@ guix build -d -m "$module_dir/manifest.scm" \
rm "$module_dir"/*.scm
if [ -n "$BASH_VERSION" ]
then
# Check whether we can load from a /dev/fd/N denoting a pipe, using this
# handy Bash-specific construct.
guix build -m <(echo '(specifications->manifest (list "guile"))') -n
fi
# Using 'GUIX_BUILD_OPTIONS'.
GUIX_BUILD_OPTIONS="--dry-run --no-grafts"
export GUIX_BUILD_OPTIONS