02/04: hurd-boot: Explain why 'getxattr' cannot be used on GNU/Hurd.

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit b5e334aeb8ab6ec68d19bcdb9b6f9cb5bea40ba0
Author: Ludovic Courtès <ludo@gnu.org>
AuthorDate: Sun Nov 27 23:41:16 2022 +0100

    hurd-boot: Explain why 'getxattr' cannot be used on GNU/Hurd.
    
    This is a followup to f25e8f76fec03e5a31c221e7427d6962ece1aa67.
    
    * gnu/build/hurd-boot.scm (translated?): Clarify why 'getxattr' cannot
    be used on GNU/Hurd.
---
 gnu/build/hurd-boot.scm | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gnu/build/hurd-boot.scm b/gnu/build/hurd-boot.scm
index ad8ffccea6..99e5c75e11 100644
--- a/gnu/build/hurd-boot.scm
+++ b/gnu/build/hurd-boot.scm
@@ -127,6 +127,9 @@ set."
 
 (define (translated? file-name)
   "Return true if a translator is installed on FILE-NAME."
+  ;; On GNU/Hurd, 'getxattr' in glibc opens the file without O_NOTRANS, and
+  ;; then, for "gnu.translator", it calls 'file_get_translator', resulting in
+  ;; EOPNOTSUPP (conversely, 'showtrans' opens the file with O_NOTRANS).
   (if (string-contains %host-type "linux-gnu")
       (passive-translator-xattr? file-name)
       (passive-translator-installed? file-name)))