diff options
| -rw-r--r-- | gnu/build/install.scm | 60 |
1 files changed, 40 insertions, 20 deletions
diff --git a/gnu/build/install.scm b/gnu/build/install.scm index f5c8407b89..33a9616c0d 100644 --- a/gnu/build/install.scm +++ b/gnu/build/install.scm @@ -1,6 +1,7 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org> ;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com> +;;; Copyright © 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com> ;;; ;;; This file is part of GNU Guix. ;;; @@ -56,19 +57,24 @@ that the fonts, background images, etc. referred to by BOOTCFG are not GC'd." (define* (evaluate-populate-directive directive target #:key (default-gid 0) - (default-uid 0)) + (default-uid 0) + (error-on-dangling-symlink? #t)) "Evaluate DIRECTIVE, an sexp describing a file or directory to create under directory TARGET. DEFAULT-UID and DEFAULT-GID are the default UID and GID in the context of the caller. If the directive matches those defaults then, -'chown' won't be run." +'chown' won't be run. When ERROR-ON-DANGLING-SYMLINK? is true, abort with an +error when a dangling symlink would be created." + (define target* (if (string-suffix? "/" target) + target + (string-append target "/"))) (let loop ((directive directive)) (catch 'system-error (lambda () (match directive (('directory name) - (mkdir-p (string-append target name))) + (mkdir-p (string-append target* name))) (('directory name uid gid) - (let ((dir (string-append target name))) + (let ((dir (string-append target* name))) (mkdir-p dir) ;; If called from a context without "root" permissions, "chown" ;; to root will fail. In that case, do not try to run "chown" @@ -78,27 +84,38 @@ the context of the caller. If the directive matches those defaults then, (chown dir uid gid)))) (('directory name uid gid mode) (loop `(directory ,name ,uid ,gid)) - (chmod (string-append target name) mode)) + (chmod (string-append target* name) mode)) (('file name) - (call-with-output-file (string-append target name) + (call-with-output-file (string-append target* name) (const #t))) (('file name (? string? content)) - (call-with-output-file (string-append target name) + (call-with-output-file (string-append target* name) (lambda (port) (display content port)))) ((new '-> old) - (let try () - (catch 'system-error - (lambda () - (symlink old (string-append target new))) - (lambda args - ;; When doing 'guix system init' on the current '/', some - ;; symlinks may already exists. Override them. - (if (= EEXIST (system-error-errno args)) - (begin - (delete-file (string-append target new)) - (try)) - (apply throw args)))))))) + (let ((new* (string-append target* new))) + (let try () + (catch 'system-error + (lambda () + (when error-on-dangling-symlink? + ;; When the symbolic link points to a relative path, + ;; checking if its target exists must be done relatively + ;; to the link location. + (unless (if (string-prefix? "/" old) + (file-exists? old) + (with-directory-excursion (dirname new*) + (file-exists? old))) + (error (format #f "symlink `~a' points to nonexistent \ +file `~a'" new* old)))) + (symlink old new*)) + (lambda args + ;; When doing 'guix system init' on the current '/', some + ;; symlinks may already exists. Override them. + (if (= EEXIST (system-error-errno args)) + (begin + (delete-file new*) + (try)) + (apply throw args))))))))) (lambda args ;; Usually we can only get here when installing to an existing root, ;; as with 'guix system init foo.scm /'. @@ -142,7 +159,10 @@ STORE." includes /etc, /var, /run, /bin/sh, etc., and all the symlinks to SYSTEM. EXTRAS is a list of directives appended to the built-in directives to populate TARGET." - (for-each (cut evaluate-populate-directive <> target) + ;; It's expected that some symbolic link targets do not exist yet, so do not + ;; error on dangling links. + (for-each (cut evaluate-populate-directive <> target + #:error-on-dangling-symlink? #f) (append (directives (%store-directory)) extras)) ;; Add system generation 1. |