From bdb32266079f13f687790426dcbe1941c6a959f0 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Fri, 17 Apr 2020 14:30:04 +0200
Subject: [PATCH] Add flag to disable the eval cache

---
 src/nix/flake.cc | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 753e9e29a..c78e6f2f1 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -976,6 +976,7 @@ struct AttrCursor : std::enable_shared_from_this<AttrCursor>
 struct CmdFlakeShow : FlakeCommand
 {
     bool showLegacy = false;
+    bool useEvalCache = true;
 
     CmdFlakeShow()
     {
@@ -983,6 +984,11 @@ struct CmdFlakeShow : FlakeCommand
             .longName("legacy")
             .description("show the contents of the 'legacyPackages' output")
             .set(&showLegacy, true);
+
+        mkFlag()
+            .longName("no-eval-cache")
+            .description("do not use the flake evaluation cache")
+            .handler([&]() { useEvalCache = false; });
     }
 
     std::string description() override
@@ -1111,7 +1117,7 @@ struct CmdFlakeShow : FlakeCommand
             }
         };
 
-        auto db = std::make_shared<AttrDb>(flake.getFingerprint());
+        auto db = useEvalCache ? std::make_shared<AttrDb>(flake.getFingerprint()) : nullptr;
 
         auto root = std::make_shared<AttrRoot>(db, *state,
             [&]()