buildGo{Module,Package}: add tags argument

Simpler method of setting tags rather than using some combination of buildFlags, buildFlagsArray, preBuild, etc

Using `lib.concatStringsSep ","` as space separated tags are deprecated in go.

doc/languages-frameworks/go.section.md

@@ -112,16 +112,6 @@ done
 
 Both `buildGoModule` and `buildGoPackage` can be tweaked to behave slightly differently, if the following attributes are used:
 
-### `buildFlagsArray` and `buildFlags`: {#ex-goBuildFlags-noarray}
-
-These attributes set build flags supported by `go build`. We recommend using `buildFlagsArray`.
-
-```nix
-  buildFlagsArray = [
-    "-tags=release"
-  ];
-```
-
 ### `ldflags` {#var-go-ldflags}
 
 Arguments to pass to the Go linker tool via the `-ldflags` argument of `go build`. The most common use case for this argument is to make the resulting executable aware of its own version. For example:
@@ -134,6 +124,21 @@ Arguments to pass to the Go linker tool via the `-ldflags` argument of `go build
   ];
 ```
 
+### `tags` {#var-go-tags}
+
+Arguments to pass to the Go via the `-tags` argument of `go build`. For example:
+
+```nix
+  tags = [
+    "production"
+    "sqlite"
+  ];
+```
+
+```nix
+  tags = [ "production" ] ++ lib.optionals withSqlite [ "sqlite" ];
+```
+
 ### `deleteVendor` {#var-go-deleteVendor}
 
 Removes the pre-existing vendor directory. This should only be used if the dependencies included in the vendor folder are broken or incomplete.

pkgs/development/go-modules/generic/default.nix

@@ -10,6 +10,9 @@
 # Go linker flags, passed to go via -ldflags
 , ldflags ? []
 
+# Go tags, passed to go via -tag
+, tags ? []
+
 # A function to override the go-modules derivation
 , overrideModAttrs ? (_oldAttrs : {})
 
@@ -156,7 +159,7 @@ let
         echo "$d" | grep -q "\(/_\|examples\|Godeps\|testdata\)" && return 0
         [ -n "$excludedPackages" ] && echo "$d" | grep -q "$excludedPackages" && return 0
         local OUT
-        if ! OUT="$(go $cmd $buildFlags "''${buildFlagsArray[@]}" ''${ldflags:+-ldflags="$ldflags"} -v -p $NIX_BUILD_CORES $d 2>&1)"; then
+        if ! OUT="$(go $cmd $buildFlags "''${buildFlagsArray[@]}" ''${tags:+-tags=${lib.concatStringsSep "," tags}} ''${ldflags:+-ldflags="$ldflags"} -v -p $NIX_BUILD_CORES $d 2>&1)"; then
           if ! echo "$OUT" | grep -qE '(no( buildable| non-test)?|build constraints exclude all) Go (source )?files'; then
             echo "$OUT" >&2
             return 1

pkgs/development/go-packages/generic/default.nix

@@ -10,6 +10,9 @@
 # Go linker flags, passed to go via -ldflags
 , ldflags ? []
 
+# Go tags, passed to go via -tag
+, tags ? []
+
 # We want parallel builds by default
 , enableParallelBuilding ? true
 
@@ -151,7 +154,7 @@ let
         echo "$d" | grep -q "\(/_\|examples\|Godeps\)" && return 0
         [ -n "$excludedPackages" ] && echo "$d" | grep -q "$excludedPackages" && return 0
         local OUT
-        if ! OUT="$(go $cmd $buildFlags "''${buildFlagsArray[@]}" ''${ldflags:+-ldflags="$ldflags"} -v -p $NIX_BUILD_CORES $d 2>&1)"; then
+        if ! OUT="$(go $cmd $buildFlags "''${buildFlagsArray[@]}" ''${tags:+-tags=${lib.concatStringsSep "," tags}} ''${ldflags:+-ldflags="$ldflags"} -v -p $NIX_BUILD_CORES $d 2>&1)"; then
           if ! echo "$OUT" | grep -qE '(no( buildable| non-test)?|build constraints exclude all) Go (source )?files'; then
             echo "$OUT" >&2
             return 1