bug#26271: 'guix system' does not support common build option '--root'

bug#26271: 'guix system' does not support common build option '--root'

[Chris Marusich]

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Hi,

The manual says ((guix) Invoking guix system) that the options to 'guix
system' "can contain any of the common build options".  Although some
common build options (e.g. '--fallback') do seem to work, I have noticed
that the '--root' option does not.  Consider the following:

--8<---------------cut here---------------start------------->8---
[0] marusich@garuda:/tmp
$ GUIX_BUILD_OPTIONS=--root=foo guix system disk-image --image-size=1G ~/guix/gnu/system/install.scm
guix system: error: root=foo: unrecognized option
[1] marusich@garuda:/tmp
$ guix system disk-image --root=foo --image-size=1G ~/guix/gnu/system/install.scm
guix system: error: root=foo: unrecognized option
[1] marusich@garuda:/tmp
$ guix system disk-image -r foo --image-size=1G ~/guix/gnu/system/install.scm
guix system: error: r: unrecognized option
[1] marusich@garuda:/tmp
$ 
--8<---------------cut here---------------end--------------->8---

I expected the 'guix system' command to run normally and produce an
indirect GC root at path /tmp/foo.  Instead, the command failed.  The
'--root' option does work with 'guix build'.  Is the documentation
incorrect, or is this a bug?

-- 
Chris

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bug#26271: 'guix system' does not support common build option '--root'

[Ludovic Courtès]

Hi Chris,

Chris Marusich <cmmarusich@gmail.com> skribis:

> The manual says ((guix) Invoking guix system) that the options to 'guix
> system' "can contain any of the common build options".  Although some
> common build options (e.g. '--fallback') do seem to work, I have noticed
> that the '--root' option does not.  Consider the following:

That’s because ‘--root’ is not a “common build option” in the sense of
"(guix) Common Build Options".  :-)

That said, I agree we should either make it a common option (i.e., add
it to ‘%standard-build-options’ in (guix scripts build)) or add it
explicitly to ‘guix system’.  The latter may be simpler.

Thoughts?

Ludo’.

bug#26271: 'guix system' does not support common build option '--root'

[Chris Marusich]

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ludo@gnu.org (Ludovic Courtès) writes:

> Hi Chris,
>
> Chris Marusich <cmmarusich@gmail.com> skribis:
>
>> The manual says ((guix) Invoking guix system) that the options to 'guix
>> system' "can contain any of the common build options".  Although some
>> common build options (e.g. '--fallback') do seem to work, I have noticed
>> that the '--root' option does not.  Consider the following:
>
> That’s because ‘--root’ is not a “common build option” in the sense of
> "(guix) Common Build Options".  :-)
>
> That said, I agree we should either make it a common option (i.e., add
> it to ‘%standard-build-options’ in (guix scripts build)) or add it
> explicitly to ‘guix system’.  The latter may be simpler.
>
> Thoughts?

As long as 'guix system' will create an indirect gc root as expected,
regardless of whether '--root' was specified in the environment variable
for build options or as a command-line option for the 'guix system'
command, adding it explicitly to 'guix system' seems OK to me.

I'll see if I can submit a patch later this week.

-- 
Chris

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bug#26271: 'guix system' does not support common build option '--root'

[Chris Marusich]

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Chris Marusich <cmmarusich@gmail.com> writes:

> ludo@gnu.org (Ludovic Courtès) writes:
>
>> Hi Chris,
>>
>> Chris Marusich <cmmarusich@gmail.com> skribis:
>>
>>> The manual says ((guix) Invoking guix system) that the options to 'guix
>>> system' "can contain any of the common build options".  Although some
>>> common build options (e.g. '--fallback') do seem to work, I have noticed
>>> that the '--root' option does not.  Consider the following:
>>
>> That’s because ‘--root’ is not a “common build option” in the sense of
>> "(guix) Common Build Options".  :-)
>>
>> That said, I agree we should either make it a common option (i.e., add
>> it to ‘%standard-build-options’ in (guix scripts build)) or add it
>> explicitly to ‘guix system’.  The latter may be simpler.
>>
>> Thoughts?
>
> As long as 'guix system' will create an indirect gc root as expected,
> regardless of whether '--root' was specified in the environment variable
> for build options or as a command-line option for the 'guix system'
> command, adding it explicitly to 'guix system' seems OK to me.
>
> I'll see if I can submit a patch later this week.

I've attached a small patch series which adds support.  Please let me
know what you think.  (If you prefer that I send the patches to you via
some other email list or something, please let me know.)  I've verified
manually that the patches fix the issue.  For example:

--8<---------------cut here---------------start------------->8---
$ GUIX_BUILD_OPTIONS='--root=my-indirect-root' ./pre-inst-env guix system disk-image ~/guix/gnu/system/install.scm
/gnu/store/qr83vk7lifm63jscrv1gfqzj80zwkmca-disk-image
$ ls -l | grep indir
lrwxrwxrwx 1 marusich users       54 Apr  3 23:44 my-indirect-root -> /gnu/store/qr83vk7lifm63jscrv1gfqzj80zwkmca-disk-image
$ ls -l /var/guix/gcroots/auto/ | grep indir
lrwxrwxrwx 1 root root 36 Apr  3 23:44 wk6bx8f7xjq8ab7dz683n64ly21dyw8x -> /home/marusich/guix/my-indirect-root
--8<---------------cut here---------------end--------------->8---

It works the same when I pass the option directly on the command line as
'--root=foo' or '-r foo', too.

-- 
Chris

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From ccf03e4bb5d5c2d3a47efdf64e36a7d903bfb2c5 Mon Sep 17 00:00:00 2001
From: Chris Marusich <cmmarusich@gmail.com>
Date: Mon, 3 Apr 2017 23:47:22 -0700
Subject: [PATCH 1/2] build: Export register-root procedure.

* guix/scripts/build.scm: Export register-root procedure.
---
 guix/scripts/build.scm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/guix/scripts/build.scm b/guix/scripts/build.scm
index 68402fda1..ba47b1232 100644
--- a/guix/scripts/build.scm
+++ b/guix/scripts/build.scm
@@ -51,7 +51,8 @@
             options->transformation
             show-transformation-options-help
 
-            guix-build))
+            guix-build
+            register-root))
 
 (define %default-log-urls
   ;; Default base URLs for build logs.
-- 
2.12.0


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From e96c877459555f4cf868fb5fe4579183f6a773d5 Mon Sep 17 00:00:00 2001
From: Chris Marusich <cmmarusich@gmail.com>
Date: Mon, 3 Apr 2017 23:49:22 -0700
Subject: [PATCH 2/2] system: Support the --root option in 'guix system'.

Fixes <https://bugs.gnu.org/26271>.

* guix/scripts/system.scm (perform-action): Add parameters 'store' and
  'gc-root'.  Update docstring.
  (perform-action) [gc-root]: Add an indirect GC root using store.
  (%options): Add 'root'.
  (process-action): Pass 'store' and 'root' to perform-action.
---
 guix/scripts/system.scm | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 144a7fd37..54a9e1d37 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -589,19 +589,24 @@ PATTERN, a string.  When PATTERN is #f, display all the system generations."
     (warning (_ "Consider running 'guix pull' before 'reconfigure'.~%"))
     (warning (_ "Failing to do that may downgrade your system!~%"))))
 
-(define* (perform-action action os
+(define* (perform-action store action os
                          #:key grub? dry-run? derivations-only?
                          use-substitutes? device target
                          image-size full-boot?
-                         (mappings '()))
-  "Perform ACTION for OS.  GRUB? specifies whether to install GRUB; DEVICE is
-the target devices for GRUB; TARGET is the target root directory; IMAGE-SIZE
-is the size of the image to be built, for the 'vm-image' and 'disk-image'
-actions.  FULL-BOOT? is used for the 'vm' action; it determines whether to
-boot directly to the kernel or to the bootloader.
+                         (mappings '())
+                         (gc-root #f))
+  "Perform ACTION for OS using STORE, which is an open connection to the
+store.  GRUB?  specifies whether to install GRUB; DEVICE is the target devices
+for GRUB; TARGET is the target root directory; IMAGE-SIZE is the size of the
+image to be built, for the 'vm-image' and 'disk-image' actions.  FULL-BOOT? is
+used for the 'vm' action; it determines whether to boot directly to the kernel
+or to the bootloader.
 
 When DERIVATIONS-ONLY? is true, print the derivation file name(s) without
-building anything."
+building anything.
+
+When GC-ROOT is a path, also make that path an indirect root of the build
+output when building a system derivation, such as a disk image."
   (define println
     (cut format #t "~a~%" <>))
 
@@ -666,7 +671,10 @@ building anything."
                       #:device device))
             (else
              ;; All we had to do was to build SYS.
-             (return (derivation->output-path sys))))))))
+             (return (let ((output-path (derivation->output-path sys)))
+                       (if gc-root
+                           (register-root store (list output-path) gc-root)
+                           output-path)))))))))
 
 (define (export-extension-graph os port)
   "Export the service extension graph of OS to PORT."
@@ -797,6 +805,9 @@ Some ACTIONS support additional ARGS.\n"))
                  (lambda (opt name arg result)
                    (alist-cons 'system arg
                                (alist-delete 'system result eq?))))
+         (option '(#\r "root") #t #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'gc-root arg result)))
          %standard-build-options))
 
 (define %default-options
@@ -850,7 +861,7 @@ resulting from command-line parsing."
             ((shepherd-graph)
              (export-shepherd-graph os (current-output-port)))
             (else
-             (perform-action action os
+             (perform-action store action os
                              #:dry-run? dry?
                              #:derivations-only? (assoc-ref opts
                                                             'derivations-only?)
@@ -863,7 +874,8 @@ resulting from command-line parsing."
                                                       (_ #f))
                                                     opts)
                              #:grub? grub?
-                             #:target target #:device device))))
+                             #:target target #:device device
+                             #:gc-root (assoc-ref opts 'gc-root)))))
         #:system system))))
 
 (define (process-command command args opts)
-- 
2.12.0


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bug#26271: 'guix system' does not support common build option '--root'

[Ludovic Courtès]

Hi Chris,

Chris Marusich <cmmarusich@gmail.com> skribis:

> I've attached a small patch series which adds support.  Please let me
> know what you think.  (If you prefer that I send the patches to you via
> some other email list or something, please let me know.)  I've verified
> manually that the patches fix the issue.  For example:
>
> $ GUIX_BUILD_OPTIONS='--root=my-indirect-root' ./pre-inst-env guix system disk-image ~/guix/gnu/system/install.scm
> /gnu/store/qr83vk7lifm63jscrv1gfqzj80zwkmca-disk-image
> $ ls -l | grep indir
> lrwxrwxrwx 1 marusich users       54 Apr  3 23:44 my-indirect-root -> /gnu/store/qr83vk7lifm63jscrv1gfqzj80zwkmca-disk-image
> $ ls -l /var/guix/gcroots/auto/ | grep indir
> lrwxrwxrwx 1 root root 36 Apr  3 23:44 wk6bx8f7xjq8ab7dz683n64ly21dyw8x -> /home/marusich/guix/my-indirect-root
>
> It works the same when I pass the option directly on the command line as
> '--root=foo' or '-r foo', too.

Nice.

> From ccf03e4bb5d5c2d3a47efdf64e36a7d903bfb2c5 Mon Sep 17 00:00:00 2001
> From: Chris Marusich <cmmarusich@gmail.com>
> Date: Mon, 3 Apr 2017 23:47:22 -0700
> Subject: [PATCH 1/2] build: Export register-root procedure.
>
> * guix/scripts/build.scm: Export register-root procedure.

Applied.

> From e96c877459555f4cf868fb5fe4579183f6a773d5 Mon Sep 17 00:00:00 2001
> From: Chris Marusich <cmmarusich@gmail.com>
> Date: Mon, 3 Apr 2017 23:49:22 -0700
> Subject: [PATCH 2/2] system: Support the --root option in 'guix system'.
>
> Fixes <https://bugs.gnu.org/26271>.
>
> * guix/scripts/system.scm (perform-action): Add parameters 'store' and
>   'gc-root'.  Update docstring.
>   (perform-action) [gc-root]: Add an indirect GC root using store.
>   (%options): Add 'root'.
>   (process-action): Pass 'store' and 'root' to perform-action.

[...]

> -(define* (perform-action action os
> +(define* (perform-action store action os
>                           #:key grub? dry-run? derivations-only?
>                           use-substitutes? device target
>                           image-size full-boot?
> -                         (mappings '()))


[...]

>               ;; All we had to do was to build SYS.
> -             (return (derivation->output-path sys))))))))
> +             (return (let ((output-path (derivation->output-path sys)))
> +                       (if gc-root
> +                           (register-root store (list output-path) gc-root)
> +                           output-path)))))))))

‘perform-action’ is a monadic procedure; IOW, the ‘store’ parameter is
already threaded into it.  Thus, instead of adding an explicit ‘store’
parameter, which must “lift” ‘register-root’ in the store monad:

  (define register-root*
    (store-lift register-root))

and then use it like a normal monadic procedure:

  (let ((output (derivation->output-path sys)))
    (mbegin %store-monad
      (mwhen gc-root
        (register-root* (list output) gc-root))
      (return output)))

Could you change this patch along these lines?

Also please make sure to mention ‘--root’ in ‘show-help’ and in
guix.texi.

Thank you!

Ludo’.

bug#26271: 'guix system' does not support common build option '--root'

[Chris Marusich]

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ludo@gnu.org (Ludovic Courtès) writes:

>> From ccf03e4bb5d5c2d3a47efdf64e36a7d903bfb2c5 Mon Sep 17 00:00:00 2001
>> From: Chris Marusich <cmmarusich@gmail.com>
>> Date: Mon, 3 Apr 2017 23:47:22 -0700
>> Subject: [PATCH 1/2] build: Export register-root procedure.
>>
>> * guix/scripts/build.scm: Export register-root procedure.
>
> Applied.

Thank you!

>> From e96c877459555f4cf868fb5fe4579183f6a773d5 Mon Sep 17 00:00:00 2001
>> From: Chris Marusich <cmmarusich@gmail.com>
>> Date: Mon, 3 Apr 2017 23:49:22 -0700
>> Subject: [PATCH 2/2] system: Support the --root option in 'guix system'.
>>
>> Fixes <https://bugs.gnu.org/26271>.
>>
>> * guix/scripts/system.scm (perform-action): Add parameters 'store' and
>>   'gc-root'.  Update docstring.
>>   (perform-action) [gc-root]: Add an indirect GC root using store.
>>   (%options): Add 'root'.
>>   (process-action): Pass 'store' and 'root' to perform-action.
>
> [...]
>
>> -(define* (perform-action action os
>> +(define* (perform-action store action os
>>                           #:key grub? dry-run? derivations-only?
>>                           use-substitutes? device target
>>                           image-size full-boot?
>> -                         (mappings '()))
>
>
> [...]
>
>>               ;; All we had to do was to build SYS.
>> -             (return (derivation->output-path sys))))))))
>> +             (return (let ((output-path (derivation->output-path sys)))
>> +                       (if gc-root
>> +                           (register-root store (list output-path) gc-root)
>> +                           output-path)))))))))
>
> ‘perform-action’ is a monadic procedure; IOW, the ‘store’ parameter is
> already threaded into it.  Thus, instead of adding an explicit ‘store’
> parameter, which must “lift” ‘register-root’ in the store monad:
>
>   (define register-root*
>     (store-lift register-root))
>
> and then use it like a normal monadic procedure:
>
>   (let ((output (derivation->output-path sys)))
>     (mbegin %store-monad
>       (mwhen gc-root
>         (register-root* (list output) gc-root))
>       (return output)))
>
> Could you change this patch along these lines?

Thank you for reminding me that we can do it this way!  I've updated the
patch and verified that it still works.

> Also please make sure to mention ‘--root’ in ‘show-help’ and in
> guix.texi.

In the attached patch series, I've mentioned '--root' in 'show-help'.
However, since there is already a link in the '(guix) Invoking guix
system)' section to the section which describes the common build options
((guix) Common Build Options), I decided not to duplicate the
documentation for '--root' in that section.

If you still think we should mention '--root' in '(guix) Invoking guix
system)', let me know and I will submit another small patch to add it.

Now we can generate system images without fear of the reaper!  The
garbage reaper, that is :-)

-- 
Chris

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From 8b768570b26d9a44ea140b0cd29383d32d37a0df Mon Sep 17 00:00:00 2001
From: Chris Marusich <cmmarusich@gmail.com>
Date: Tue, 4 Apr 2017 20:24:54 -0700
Subject: [PATCH 1/2] build: Add and export procedure 'register-root*'.

* guix/scripts/build.scm (register-root*): Add and export it.
---
 guix/scripts/build.scm | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/guix/scripts/build.scm b/guix/scripts/build.scm
index ba47b1232..6bb1f72eb 100644
--- a/guix/scripts/build.scm
+++ b/guix/scripts/build.scm
@@ -52,7 +52,8 @@
             show-transformation-options-help
 
             guix-build
-            register-root))
+            register-root
+            register-root*))
 
 (define %default-log-urls
   ;; Default base URLs for build logs.
@@ -123,6 +124,9 @@ found.  Return #f if no build log was found."
         (leave (_ "failed to create GC root `~a': ~a~%")
                root (strerror (system-error-errno args)))))))
 
+(define register-root*
+  (store-lift register-root))
+
 (define (package-with-source store p uri)
   "Return a package based on P but with its source taken from URI.  Extract
 the new package's version number from URI."
-- 
2.12.0


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From 430fdb321f3401d5a498f002291ae520d47f1dcf Mon Sep 17 00:00:00 2001
From: Chris Marusich <cmmarusich@gmail.com>
Date: Mon, 3 Apr 2017 23:49:22 -0700
Subject: [PATCH 2/2] system: Support the --root option in 'guix system'.

Fixes <https://bugs.gnu.org/26271>.

* guix/scripts/system.scm (perform-action): Add #:gc-root parameter and honor
  it.
  (show-help): Document the --root option.
  (%options): Add 'root'.
  (process-action): Pass 'root' option to perform-action as #:gc-root.
---
 guix/scripts/system.scm | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/guix/scripts/system.scm b/guix/scripts/system.scm
index 144a7fd37..d867465dd 100644
--- a/guix/scripts/system.scm
+++ b/guix/scripts/system.scm
@@ -593,7 +593,8 @@ PATTERN, a string.  When PATTERN is #f, display all the system generations."
                          #:key grub? dry-run? derivations-only?
                          use-substitutes? device target
                          image-size full-boot?
-                         (mappings '()))
+                         (mappings '())
+                         (gc-root #f))
   "Perform ACTION for OS.  GRUB? specifies whether to install GRUB; DEVICE is
 the target devices for GRUB; TARGET is the target root directory; IMAGE-SIZE
 is the size of the image to be built, for the 'vm-image' and 'disk-image'
@@ -601,7 +602,10 @@ actions.  FULL-BOOT? is used for the 'vm' action; it determines whether to
 boot directly to the kernel or to the bootloader.
 
 When DERIVATIONS-ONLY? is true, print the derivation file name(s) without
-building anything."
+building anything.
+
+When GC-ROOT is a path, also make that path an indirect root of the build
+output when building a system derivation, such as a disk image."
   (define println
     (cut format #t "~a~%" <>))
 
@@ -665,8 +669,11 @@ building anything."
                       #:grub.cfg (derivation->output-path grub.cfg)
                       #:device device))
             (else
-             ;; All we had to do was to build SYS.
-             (return (derivation->output-path sys))))))))
+             ;; All we had to do was to build SYS and maybe register an
+             ;; indirect GC root.
+             (mwhen gc-root
+               (register-root* (list (derivation->output-path sys))
+                               gc-root))))))))
 
 (define (export-extension-graph os port)
   "Export the service extension graph of OS to PORT."
@@ -741,6 +748,10 @@ Some ACTIONS support additional ARGS.\n"))
   (display (_ "
       --share=SPEC       for 'vm', share host file system according to SPEC"))
   (display (_ "
+  -r, --root=FILE        for 'vm', 'vm-image', 'disk-image', 'container',
+                         and 'build', make FILE a symlink to the result, and
+                         register it as a garbage collector root."))
+  (display (_ "
       --expose=SPEC      for 'vm', expose host file system according to SPEC"))
   (display (_ "
       --full-boot        for 'vm', make a full boot sequence"))
@@ -797,6 +808,9 @@ Some ACTIONS support additional ARGS.\n"))
                  (lambda (opt name arg result)
                    (alist-cons 'system arg
                                (alist-delete 'system result eq?))))
+         (option '(#\r "root") #t #f
+                 (lambda (opt name arg result)
+                   (alist-cons 'gc-root arg result)))
          %standard-build-options))
 
 (define %default-options
@@ -863,7 +877,8 @@ resulting from command-line parsing."
                                                       (_ #f))
                                                     opts)
                              #:grub? grub?
-                             #:target target #:device device))))
+                             #:target target #:device device
+                             #:gc-root (assoc-ref opts 'gc-root)))))
         #:system system))))
 
 (define (process-command command args opts)
-- 
2.12.0


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bug#26271: 'guix system' does not support common build option '--root'

[Ludovic Courtès]

Hi,

Chris Marusich <cmmarusich@gmail.com> skribis:

> In the attached patch series, I've mentioned '--root' in 'show-help'.
> However, since there is already a link in the '(guix) Invoking guix
> system)' section to the section which describes the common build options
> ((guix) Common Build Options), I decided not to duplicate the
> documentation for '--root' in that section.
>
> If you still think we should mention '--root' in '(guix) Invoking guix
> system)', let me know and I will submit another small patch to add it.

I decided to add --root under “Invoking guix system” because “Common
Build Options” doesn’t mention it.

> Now we can generate system images without fear of the reaper!  The
> garbage reaper, that is :-)

Heheh.  :-)

Note that previously the image could be GC’d only once ‘guix system’ had
completed.

> From 8b768570b26d9a44ea140b0cd29383d32d37a0df Mon Sep 17 00:00:00 2001
> From: Chris Marusich <cmmarusich@gmail.com>
> Date: Tue, 4 Apr 2017 20:24:54 -0700
> Subject: [PATCH 1/2] build: Add and export procedure 'register-root*'.
>
> * guix/scripts/build.scm (register-root*): Add and export it.

Applied.

> From 430fdb321f3401d5a498f002291ae520d47f1dcf Mon Sep 17 00:00:00 2001
> From: Chris Marusich <cmmarusich@gmail.com>
> Date: Mon, 3 Apr 2017 23:49:22 -0700
> Subject: [PATCH 2/2] system: Support the --root option in 'guix system'.
>
> Fixes <https://bugs.gnu.org/26271>.
>
> * guix/scripts/system.scm (perform-action): Add #:gc-root parameter and honor
>   it.
>   (show-help): Document the --root option.
>   (%options): Add 'root'.
>   (process-action): Pass 'root' option to perform-action as #:gc-root.

Applied with minor changes:

> @@ -665,8 +669,11 @@ building anything."
>                        #:grub.cfg (derivation->output-path grub.cfg)
>                        #:device device))
>              (else
> -             ;; All we had to do was to build SYS.
> -             (return (derivation->output-path sys))))))))
> +             ;; All we had to do was to build SYS and maybe register an
> +             ;; indirect GC root.
> +             (mwhen gc-root
> +               (register-root* (list (derivation->output-path sys))
> +                               gc-root))))))))

I changed it so that it would still return the output file name.

>    (display (_ "
> +  -r, --root=FILE        for 'vm', 'vm-image', 'disk-image', 'container',
> +                         and 'build', make FILE a symlink to the result, and
> +                         register it as a garbage collector root."))

I removed the period for consistency.

Thanks!

Ludo’.