4 files changed, 8 insertions, 7 deletions
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 47a905c816cb..b8613427e0fa 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -156,7 +156,7 @@ public:
         abort();
     }
 
-    void trace(const format & f);
+    void trace(const FormatOrString & fs);
 
     string getName()
     {
@@ -417,9 +417,9 @@ void Goal::amDone(ExitCode result)
 }
 
 
-void Goal::trace(const format & f)
+void Goal::trace(const FormatOrString & fs)
 {
-    debug(format("%1%: %2%") % name % f);
+    debug("%1%: %2%", name, fs.s);
 }
 
 
@@ -1189,7 +1189,7 @@ void DerivationGoal::outputsSubstituted()
     for (auto & i : drv->inputSrcs) {
         if (worker.store.isValidPath(i)) continue;
         if (!settings.useSubstitutes)
-            throw Error(format("dependency of '%1%' of '%2%' does not exist, and substitution is disabled")
+            throw Error(format("dependency '%1%' of '%2%' does not exist, and substitution is disabled")
                 % i % drvPath);
         addWaitee(worker.makeSubstitutionGoal(i));
     }
diff --git a/src/libstore/download.cc b/src/libstore/download.cc
index 5ab625f42288..9d9f1153f4d5 100644
--- a/src/libstore/download.cc
+++ b/src/libstore/download.cc
@@ -195,6 +195,7 @@ struct CurlDownloader : public Downloader
             if (readOffset == request.data->length())
                 return 0;
             auto count = std::min(size * nitems, request.data->length() - readOffset);
+            assert(count);
             memcpy(buffer, request.data->data() + readOffset, count);
             readOffset += count;
             return count;
diff --git a/src/libstore/sqlite.cc b/src/libstore/sqlite.cc
index b13001b06d57..42d40e71d8be 100644
--- a/src/libstore/sqlite.cc
+++ b/src/libstore/sqlite.cc
@@ -7,7 +7,7 @@
 
 namespace nix {
 
-[[noreturn]] void throwSQLiteError(sqlite3 * db, const format & f)
+[[noreturn]] void throwSQLiteError(sqlite3 * db, const FormatOrString & fs)
 {
     int err = sqlite3_errcode(db);
 
@@ -21,7 +21,7 @@ namespace nix {
             : fmt("SQLite database '%s' is busy", path));
     }
     else
-        throw SQLiteError("%s: %s (in '%s')", f.str(), sqlite3_errstr(err), path);
+        throw SQLiteError("%s: %s (in '%s')", fs.s, sqlite3_errstr(err), path);
 }
 
 SQLite::SQLite(const Path & path)
diff --git a/src/libstore/sqlite.hh b/src/libstore/sqlite.hh
index 14a7a0dd8996..115679b84159 100644
--- a/src/libstore/sqlite.hh
+++ b/src/libstore/sqlite.hh
@@ -93,7 +93,7 @@ struct SQLiteTxn
 MakeError(SQLiteError, Error);
 MakeError(SQLiteBusy, SQLiteError);
 
-[[noreturn]] void throwSQLiteError(sqlite3 * db, const format & f);
+[[noreturn]] void throwSQLiteError(sqlite3 * db, const FormatOrString & fs);
 
 void handleSQLiteBusy(const SQLiteBusy & e);