[bug#47295] [PATCH 1/2] substitute: Emit a single newline upon completion.

[Ludovic Courtès]

The immediate effect is that, with '--verbosity=1', only two lines are
displayed for each substitute, instead of two lines followed by an empty
line.

* guix/scripts/substitute.scm (process-substitution): Emit a single
newline upon completion when PRINT-BUILD-TRACE? is true.
---
 guix/scripts/substitute.scm | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/guix/scripts/substitute.scm b/guix/scripts/substitute.scm
index f4042906c8..d0b4ef9fc2 100755
--- a/guix/scripts/substitute.scm
+++ b/guix/scripts/substitute.scm
@@ -551,8 +551,11 @@ the current output port."
       (every (compose zero? cdr waitpid) pids)
 
       ;; Skip a line after what 'progress-reporter/file' printed, and another
-      ;; one to visually separate substitutions.
-      (display "\n\n" (current-error-port))
+      ;; one to visually separate substitutions.  When PRINT-BUILD-TRACE? is
+      ;; true, leave it up to (guix status) to prettify things.
+      (newline (current-error-port))
+      (unless print-build-trace?
+        (newline (current-error-port)))
 
       ;; Check whether we got the data announced in NARINFO.
       (let ((actual (get-hash)))
-- 
2.31.0