minor Nix fixes

nix/go-ethereum.nix

@@ -17,7 +17,9 @@ buildGoModule {
 
     src = fetchGit {
         url = "https://github.com/ethereum/go-ethereum.git";
+        # url = /path/to/repo/go-ethereum.git;
         ref = "refs/tags/${tag_version}";
+        shallow = true;
     };
 
     proxyVendor = false;
@@ -33,8 +35,8 @@ buildGoModule {
 
     ## Fix for usb-related segmentation faults on darwin
     propagatedBuildInputs = lib.optionals stdenv.hostPlatform.isDarwin [
-       pkgs.libobjc
-       pkgs.IOKit
+        pkgs.libobjc
+        pkgs.IOKit
     ];
 
     # passthru.tests = { inherit (nixosTests) geth; };

nix/shell.nix

@@ -41,6 +41,10 @@ pkgs.mkShellNoCC {
         export PYTHONPYCACHEPREFIX=$HOME/.cache/pycache
         export PATH=$pwd/cmds:$pwd/.bin-override:$HOME/.local/bin:$PATH
         export LANG="en_US.UTF-8"
+        export HISTFILESIZE=2000
+        export HISTSIZE=2000
+        export HISTCONTROL="ignoreboth"
+        export HISTFILE=$pwd/.bash_history
 
         [ "$UID" == 0 ] || do_bin_override
     '';