nix run -f channel:nixos-20.03

Switch from nix `channel:nixpkgs-unstable` to `channel:nixos-20.03` for better stability.

Signed-off-by: Wong Hoi Sing Edison <hswong3i@gmail.com>

Makefile

@@ -106,7 +106,7 @@ binary: cmd/skopeo
 # Update nix/nixpkgs.json its latest master commit
 .PHONY: nixpkgs
 nixpkgs:
-	@nix run -f channel:nixpkgs-unstable nix-prefetch-git -c nix-prefetch-git \
+	@nix run -f channel:nixos-20.03 nix-prefetch-git -c nix-prefetch-git \
 		--no-deepClone https://github.com/nixos/nixpkgs > nix/nixpkgs.json
 
 # Build w/o using containers

nix/default.nix

@@ -11,8 +11,11 @@ let
   });
 
   static = pkg: pkg.overrideAttrs(x: {
-    configureFlags = (x.configureFlags or []) ++
-      [ "--without-shared" "--disable-shared" ];
+    doCheck = false;
+    configureFlags = (x.configureFlags or []) ++ [
+      "--without-shared"
+      "--disable-shared"
+    ];
     dontDisableStatic = true;
     enableSharedExecutables = false;
     enableStatic = true;
@@ -27,6 +30,7 @@ let
     nativeBuildInputs = [ git go-md2man installShellFiles makeWrapper pkg-config ];
     buildInputs = [ glibc glibc.static gpgme libassuan libgpgerror ];
     prePatch = ''
+      export CFLAGS='-static'
       export LDFLAGS='-s -w -static-libgcc -static'
       export EXTRA_LDFLAGS='-s -w -linkmode external -extldflags "-static -lm"'
       export BUILDTAGS='static netgo exclude_graphdriver_btrfs exclude_graphdriver_devicemapper'

nix/nixpkgs.json

@@ -1,10 +1,7 @@
 {
   "url": "https://github.com/nixos/nixpkgs",
-  "rev": "78e324d2726127828a15f87a75b4d3199a8955ec",
-  "date": "2020-06-16T18:23:14-07:00",
-  "path": "/nix/store/bwhp0061k3fk00j8fskpfak261jdcjl6-nixpkgs",
-  "sha256": "1j58aa9ngdmvbnds4x4a497nynj390dzqyb5yrvmhjc7k9anq6jm",
-  "fetchSubmodules": false,
-  "deepClone": false,
-  "leaveDotGit": false
+  "rev": "87c5724af9f61be5e77034229078960690c1abe2",
+  "date": "2020-06-28T22:14:24+01:00",
+  "sha256": "1vg6iajb945b33nx674nnask6wai8zkjd4m0i9fcpdkwhwr0s46s",
+  "fetchSubmodules": false
 }