Make the logger customisable

Add a new `--log-format` cli argument to change the format of the logs.
The possible values are
- raw (the default one for old-style commands)
- bar (the default one for new-style commands)
- bar-with-logs (equivalent to `--print-build-logs`)
- internal-json (the internal machine-readable json format)

1 files changed, 9 insertions, 0 deletions

diff --git a/src/libmain/common-args.cc b/src/libmain/common-args.cc
index 51e199ea5..a0cccceb4 100644
--- a/src/libmain/common-args.cc
+++ b/src/libmain/common-args.cc
@@ -1,5 +1,6 @@
 #include "common-args.hh"
 #include "globals.hh"
+#include "loggers.hh"
 
 namespace nix {
 
@@ -39,6 +40,14 @@ MixCommonArgs::MixCommonArgs(const string & programName)
     });
 
     addFlag({
+        .longName = "log-format",
+        .description = "Format of the logs. One of \"raw\", \"internal-json\", \"bar\" "
+                        "or \"bar-with-logs\".",
+        .labels = {"format"},
+        .handler = {[](std::string format) { setLogFormat(format); }},
+    });
+
+    addFlag({
         .longName = "max-jobs",
         .shortName = 'j',
         .description = "maximum number of parallel builds",