6 files changed, 34 insertions, 7 deletions

diff --git a/src/libmain/common-args.hh b/src/libmain/common-args.hh
index f180d83ce..e7ed0d934 100644
--- a/src/libmain/common-args.hh
+++ b/src/libmain/common-args.hh
@@ -1,4 +1,5 @@
 #pragma once
+///@file
 
 #include "args.hh"
 
diff --git a/src/libmain/loggers.hh b/src/libmain/loggers.hh
index f3c759193..e5721420c 100644
--- a/src/libmain/loggers.hh
+++ b/src/libmain/loggers.hh
@@ -1,4 +1,5 @@
 #pragma once
+///@file
 
 #include "types.hh"
 
diff --git a/src/libmain/progress-bar.cc b/src/libmain/progress-bar.cc
index e9205a5e5..6600ec177 100644
--- a/src/libmain/progress-bar.cc
+++ b/src/libmain/progress-bar.cc
@@ -72,6 +72,7 @@ private:
         uint64_t corruptedPaths = 0, untrustedPaths = 0;
 
         bool active = true;
+        bool paused = false;
         bool haveUpdate = true;
     };
 
@@ -120,16 +121,28 @@ public:
         updateThread.join();
     }
 
+    void pause() override {
+        state_.lock()->paused = true;
+        writeToStderr("\r\e[K");
+    }
+
+    void resume() override {
+        state_.lock()->paused = false;
+        writeToStderr("\r\e[K");
+        state_.lock()->haveUpdate = true;
+        updateCV.notify_one();
+    }
+
     bool isVerbose() override
     {
         return printBuildLogs;
     }
 
-    void log(Verbosity lvl, const FormatOrString & fs) override
+    void log(Verbosity lvl, std::string_view s) override
     {
         if (lvl > verbosity) return;
         auto state(state_.lock());
-        log(*state, lvl, fs.s);
+        log(*state, lvl, s);
     }
 
     void logEI(const ErrorInfo & ei) override
@@ -142,7 +155,7 @@ public:
         log(*state, ei.level, oss.str());
     }
 
-    void log(State & state, Verbosity lvl, const std::string & s)
+    void log(State & state, Verbosity lvl, std::string_view s)
     {
         if (state.active) {
             writeToStderr("\r\e[K" + filterANSIEscapes(s, !isTTY) + ANSI_NORMAL "\n");
@@ -339,7 +352,7 @@ public:
         auto nextWakeup = std::chrono::milliseconds::max();
 
         state.haveUpdate = false;
-        if (!state.active) return nextWakeup;
+        if (state.paused || !state.active) return nextWakeup;
 
         std::string line;
 
diff --git a/src/libmain/progress-bar.hh b/src/libmain/progress-bar.hh
index 3a76f8448..c3c6e3833 100644
--- a/src/libmain/progress-bar.hh
+++ b/src/libmain/progress-bar.hh
@@ -1,4 +1,5 @@
 #pragma once
+///@file
 
 #include "logging.hh"
 
diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index d4871a8e2..37664c065 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -84,8 +84,18 @@ void printMissing(ref<Store> store, const StorePathSet & willBuild,
                 downloadSizeMiB,
                 narSizeMiB);
         }
-        for (auto & i : willSubstitute)
-            printMsg(lvl, "  %s", store->printStorePath(i));
+        std::vector<const StorePath *> willSubstituteSorted = {};
+        std::for_each(willSubstitute.begin(), willSubstitute.end(),
+                   [&](const StorePath &p) { willSubstituteSorted.push_back(&p); });
+        std::sort(willSubstituteSorted.begin(), willSubstituteSorted.end(),
+                  [](const StorePath *lhs, const StorePath *rhs) {
+                    if (lhs->name() == rhs->name())
+                      return lhs->to_string() < rhs->to_string();
+                    else
+                      return lhs->name() < rhs->name();
+                  });
+        for (auto p : willSubstituteSorted)
+            printMsg(lvl, "  %s", store->printStorePath(*p));
     }
 
     if (!unknown.empty()) {
@@ -347,7 +357,7 @@ void parseCmdLine(const std::string & programName, const Strings & args,
 
 void printVersion(const std::string & programName)
 {
-    std::cout << format("%1% (Nix) %2%") % programName % nixVersion << std::endl;
+    std::cout << fmt("%1% (Nix) %2%", programName, nixVersion) << std::endl;
     if (verbosity > lvlInfo) {
         Strings cfg;
 #if HAVE_BOEHMGC
diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 1715374a6..d915a4a65 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -1,4 +1,5 @@
 #pragma once
+///@file
 
 #include "util.hh"
 #include "args.hh"