Try keeping the node dir in /tmp with separate NODE_DB

NODE_DB should actually be set.

IIRC we cannot store the socket file in the directory that gets cached,
without breaking CI, so let's keep the node dir in /tmp.

Try different way of setting NODE_DB

Fixup redundant import

.buildkite/bench-restore.sh

@@ -14,7 +14,7 @@ log=restore.log
 results=restore-$network.txt
 total_time=restore-time.txt
 
-: "${NODE_DB:=$HOME/node-db-$network}"
+export NODE_DB=$HOME/node-db-$network
 
 echo "--- Build"
 

lib/core-integration/src/Cardano/Wallet/BenchShared.hs

@@ -88,8 +88,6 @@ import Options.Applicative
     )
 import Say
     ( sayErr )
-import System.Directory
-    ( createDirectoryIfMissing )
 import System.Environment
     ( lookupEnv )
 import System.FilePath
@@ -132,16 +130,10 @@ execBenchWithNode networkConfig action = do
 
 withNetworkConfiguration :: RestoreBenchArgs -> (CardanoNodeConfig -> IO a) -> IO a
 withNetworkConfiguration args action = do
-    -- Temporary directory for storing socket and node database
-    let withNodeDir cb = case argNodeDatabaseDir args of
-            Nothing -> withSystemTempDirectory "cw-node" cb
-            Just d -> do
-                createDirectoryIfMissing True d
-                cb d
-
     let networkDir = argsNetworkDir args
     port <- fromIntegral <$> getRandomPort
-    withNodeDir $ \dir -> action CardanoNodeConfig
+    -- Temporary directory for storing socket
+    withSystemTempDirectory "cw-node" $ \dir -> action CardanoNodeConfig
         { nodeDir          = dir
         , nodeConfigFile   = networkDir </> "configuration.json"
         , nodeDatabaseDir  = fromMaybe "db" (argNodeDatabaseDir args)