3 files changed, 19 insertions(+), 1 deletions(-)

M guix/scripts/environment.scm
M guix/scripts/home.scm
M tests/guix-environment-container.sh

@@ 770,6 770,13 @@ added to the container.
 
 Preserve environment variables whose name matches the one of the regexps in
 WHILE-LIST."
+  (define tmpfs
+    (file-system
+      (device "none")
+      (mount-point "/tmp")
+      (type "tmpfs")
+      (check? #f)))
+
   (define (optional-mapping->fs mapping)
     (and (file-exists? (file-system-mapping-source mapping))
          (file-system-mapping->bind-mount mapping)))


@@ 867,6 874,7 @@ WHILE-LIST."
                       (writable? #f)))
                    reqs)))
             (file-systems (append %container-file-systems
+                                  (list tmpfs)
                                   (if network?
                                       (filter-map optional-mapping->fs
                                                   %network-file-mappings)

@@ 353,7 353,12 @@ immediately.  Return the exit status of the process in the container."
    #:namespaces (if network?
                     (delq 'net %namespaces)       ; share host network
                     %namespaces)
-   #:mounts (list (file-system
+   #:mounts (list (file-system                    ;writable /tmp
+                    (device "none")
+                    (mount-point "/tmp")
+                    (type "tmpfs")
+                    (check? #f))
+                  (file-system
                     (device "none")
                     (mount-point
                      (in-vicinity "/run/user"     ;for shepherd & co.

@@ 195,6 195,11 @@ guix environment --bootstrap --container --ad-hoc guile-bootstrap	\
      --writable-root							\
      -- guile -c '(mkdir "/whatever")'
 
+# /tmp itself is always writable.
+guix environment --bootstrap --container --ad-hoc guile-bootstrap \
+     -- guile -c '(mkdir "/tmp/foo")'
+
+
 # Check the exit code.
 
 abnormal_exit_code="