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authorLudovic Courtès <ludo@gnu.org>2021-10-26 17:09:51 +0200
committerLudovic Courtès <ludo@gnu.org>2021-11-06 23:01:21 +0100
commit5d2d87fed7efcb8f0cee040125f7768bab3df3f4 (patch)
treed3e16f855af17be7294a4a413ffa3a7404a1e1e6 /guix/scripts/environment.scm
parent3c1158ac4e5ef825a9b9a229a233fabd7cef334e (diff)
environment: Suggest command upon 'execlp' failure.
* guix/scripts/environment.scm (launch-environment): Call 'primitive-_exit' upon 'system-error. (suggest-command-name, validate-exit-status): New procedures. (launch-environment/fork): Call 'validate-exit-status'. (launch-environment/container)[exit/status*]: New procedure. Use it instead of 'exit/status'.
Diffstat (limited to 'guix/scripts/environment.scm')
-rw-r--r--guix/scripts/environment.scm48
1 files changed, 45 insertions, 3 deletions
diff --git a/guix/scripts/environment.scm b/guix/scripts/environment.scm
index cca0ad991b..8176de4a5e 100644
--- a/guix/scripts/environment.scm
+++ b/guix/scripts/environment.scm
@@ -34,6 +34,7 @@
#:use-module (guix scripts)
#:use-module (guix scripts build)
#:use-module (guix transformations)
+ #:autoload (ice-9 ftw) (scandir)
#:autoload (gnu build linux-container) (call-with-container %namespaces
user-namespace-supported?
unprivileged-user-namespace-supported?
@@ -401,7 +402,12 @@ regexps in WHITE-LIST."
(match command
((program . args)
- (apply execlp program program args))))
+ (catch 'system-error
+ (lambda ()
+ (apply execlp program program args))
+ (lambda _
+ ;; Following established convention, exit with 127 upon ENOENT.
+ (primitive-_exit 127))))))
(define (child-shell-environment shell profile manifest)
"Create a child process, load PROFILE and MANIFEST, and then run SHELL in
@@ -552,6 +558,38 @@ running in a \"container\", immune to the issue described above."))
(info (G_ "All is good! The shell gets correct environment \
variables.~%")))))
+(define (suggest-command-name profile command)
+ "COMMAND was not found in PROFILE so display a hint suggesting the closest
+command name."
+ (define not-dot?
+ (match-lambda
+ ((or "." "..") #f)
+ (_ #t)))
+
+ (match (scandir (string-append profile "/bin") not-dot?)
+ (() #f)
+ (available
+ (match command
+ ((executable _ ...)
+ ;; Look for a suggestion with a high threshold: a suggestion is
+ ;; usually better than no suggestion.
+ (let ((closest (string-closest executable available
+ #:threshold 12)))
+ (unless (or (not closest) (string=? closest executable))
+ (display-hint (format #f (G_ "Did you mean '~a'?~%")
+ closest)))))))))
+
+(define (validate-exit-status profile command status)
+ "When STATUS, an integer as returned by 'waitpid', is 127, raise a \"command
+not found\" error. Otherwise return STATUS."
+ ;; Most likely, exit value 127 means ENOENT.
+ (when (eqv? (status:exit-val status) 127)
+ (report-error (G_ "~a: command not found~%")
+ (first command))
+ (suggest-command-name profile command)
+ (exit 1))
+ status)
+
(define* (launch-environment/fork command profile manifest
#:key pure? (white-list '()))
"Run COMMAND in a new process with an environment containing PROFILE, with
@@ -563,7 +601,8 @@ regexps in WHITE-LIST."
#:pure? pure?
#:white-list white-list))
(pid (match (waitpid pid)
- ((_ . status) status)))))
+ ((_ . status)
+ (validate-exit-status profile command status))))))
(define* (launch-environment/container #:key command bash user user-mappings
profile manifest link-profile? network?
@@ -584,6 +623,9 @@ WHILE-LIST."
(and (file-exists? (file-system-mapping-source mapping))
(file-system-mapping->bind-mount mapping)))
+ (define (exit/status* status)
+ (exit/status (validate-exit-status profile command status)))
+
(mlet %store-monad ((reqs (inputs->requisites
(list (direct-store-path bash) profile))))
(return
@@ -640,7 +682,7 @@ WHILE-LIST."
'())
(map file-system-mapping->bind-mount
mappings))))
- (exit/status
+ (exit/status*
(call-with-container file-systems
(lambda ()
;; Setup global shell.