Add '--no-net' convenience flag

This flag

* Disables substituters.

* Sets the tarball-ttl to infinity (ensuring e.g. that the flake
  registry and any downloaded flakes are considered current).

* Disables retrying downloads and sets the connection timeout to the
  minimum. (So it doesn't completely disable downloads at the moment.)

(cherry picked from commit 8ea842260b4fd93315d35c5ba94b1ff99ab391d8)

1 files changed, 11 insertions, 0 deletions

diff --git a/src/libmain/common-args.cc b/src/libmain/common-args.cc
index 9e1d7cee6..0486932b2 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 "download.hh"
 
 namespace nix {
 
@@ -44,6 +45,16 @@ MixCommonArgs::MixCommonArgs(const string & programName)
             settings.set("max-jobs", s);
         });
 
+    mkFlag()
+        .longName("no-net")
+        .description("disable substituters and consider all previously downloaded files up-to-date")
+        .handler([]() {
+            settings.useSubstitutes = false;
+            settings.tarballTtl = std::numeric_limits<unsigned int>::max();
+            downloadSettings.tries = 0;
+            downloadSettings.connectTimeout = 1;
+        });
+
     std::string cat = "config";
     globalConfig.convertToArgs(*this, cat);