Fix progress bar flicker with -L

This was caused by -L calling setLogFormat() again, which caused the
creation of a new progress bar without destroying the old one. So we
had two progress bars clobbering each other.

We should change 'logger' to be a smart pointer, but I'll do that in a
future PR.

Fixes #6931.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/nix/main.cc b/src/nix/main.cc
index a8404a2ea..f434e9655 100644
--- a/src/nix/main.cc
+++ b/src/nix/main.cc
@@ -82,7 +82,7 @@ struct NixArgs : virtual MultiCommand, virtual MixCommonArgs
             .shortName = 'L',
             .description = "Print full build logs on standard error.",
             .category = loggingCategory,
-            .handler = {[&]() {setLogFormat(LogFormat::barWithLogs); }},
+            .handler = {[&]() { logger->setPrintBuildLogs(true); }},
         });
 
         addFlag({