pkg_zip doesn't seem to be working as one would expect it to

[kwestb]

I'm trying to use pkg_zip but it doesn't seem to be working.

helloworld.txt:

Hello, World!

BUILD:

load("@rules_pkg//pkg:pkg.bzl", "pkg_zip")

pkg_zip(
    name = "helloworld",
    srcs = ["helloworld.txt"],
)

WORKSPACE:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "rules_pkg",
    sha256 = "5516557c11a0f9a7fa1eda94188c12029ce5ba851451d4481eda43ff2745c0f9",
    strip_prefix = "rules_pkg-0.2.4",
    urls = ["https://github.com/bazelbuild/rules_pkg/archive/0.2.4.zip"],
)

load("@rules_pkg//pkg:deps.bzl", "rules_pkg_dependencies", "rules_pkg_register_toolchains")
rules_pkg_dependencies()
rules_pkg_register_toolchains()

When I try to run bazel build //:helloworld, I get an error:

$ bazel build //:helloworld 
ERROR: /home/kwestb/pkg_zip_test/BUILD:3:1: every rule of type pkg_zip_impl implicitly depends upon the target '@rules_pkg//:build_zip', but this target could not be found because of: error loading package '@rules_pkg//': Unable to find package for @io_bazel_rules_go//go:def.bzl: The repository '@io_bazel_rules_go' could not be resolved.
ERROR: Analysis of target '//:helloworld' failed; build aborted: error loading package '@rules_pkg//': Unable to find package for @io_bazel_rules_go//go:def.bzl: The repository '@io_bazel_rules_go' could not be resolved.
INFO: Elapsed time: 0.557s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (5 packages loaded, 5 targets configured)

At first I thought this was simply an undeclared dependency on rules_go, so I added it to my WORKSPACE:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
    name = "io_bazel_rules_go",
    sha256 = "593a63be80bbee7313e361e91821a567b4b419b5f65473a95d39724f26d4503a",
    strip_prefix = "rules_go-0.21.0",
    urls = ["https://github.com/bazelbuild/rules_go/archive/v0.21.0.zip"],
)

http_archive(
    name = "rules_pkg",
    sha256 = "5516557c11a0f9a7fa1eda94188c12029ce5ba851451d4481eda43ff2745c0f9",
    strip_prefix = "rules_pkg-0.2.4",
    urls = ["https://github.com/bazelbuild/rules_pkg/archive/0.2.4.zip"],
)

load("@io_bazel_rules_go//go:deps.bzl", "go_rules_dependencies", "go_register_toolchains")
go_rules_dependencies()
go_register_toolchains()

load("@rules_pkg//pkg:deps.bzl", "rules_pkg_dependencies", "rules_pkg_register_toolchains")
rules_pkg_dependencies()
rules_pkg_register_toolchains()

But still no joy, this time with a different error:

$ bazel build //:helloworld 
ERROR: /home/kwestb/pkg_zip_test/BUILD:3:1: every rule of type pkg_zip_impl implicitly depends upon the target '@rules_pkg//:build_zip', but this target could not be found because of: error loading package '@rules_pkg//': Label '@rules_pkg//tools/update_deb_packages:update_deb_packages.bzl' is invalid because 'tools/update_deb_packages' is not a package; perhaps you meant to put the colon here: '@rules_pkg//:tools/update_deb_packages/update_deb_packages.bzl'?
ERROR: Analysis of target '//:helloworld' failed; build aborted: error loading package '@rules_pkg//': Label '@rules_pkg//tools/update_deb_packages:update_deb_packages.bzl' is invalid because 'tools/update_deb_packages' is not a package; perhaps you meant to put the colon here: '@rules_pkg//:tools/update_deb_packages/update_deb_packages.bzl'?
INFO: Elapsed time: 0.551s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (5 packages loaded, 5 targets configured)

Surely I must be missing something fundamental - can anyone point out the problem why I can't get this toy example to work with pkg_zip?

FYI, i'm running Bazel 2.0.0:

$ bazel info release
release 2.0.0

[nacl]

Thanks for the detailed report!

Without having run your examples, the likely cause of your problem is the strip_prefix in the rules_pkg http_archive repo declaration: the pkg directory needs to stripped too, as that's where the WORKSPACE is.

I believe your issue can be resolved by tweaking your WORKSPACE snippet to look something like this:

http_archive(
    name = "rules_pkg",
    sha256 = "5516557c11a0f9a7fa1eda94188c12029ce5ba851451d4481eda43ff2745c0f9",
    strip_prefix = "rules_pkg-0.2.4/pkg",
    urls = ["https://github.com/bazelbuild/rules_pkg/archive/0.2.4.zip"],
)

load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies", "rules_pkg_register_toolchains")
rules_pkg_dependencies()
rules_pkg_register_toolchains()

Changes are in the strip_prefix attribute and the load call.

Honestly, rules_pkg's layout isn't following best practices, and we should change it (#111).

[kwestb]

Thanks @nacl - your suggestion works. I had to make three edits, two in the WORKSPACE flle and one in the BUILD file:

diff --git a/BUILD b/BUILD
index c5adf22..8cb1722 100644
--- a/BUILD
+++ b/BUILD
@@ -1,4 +1,4 @@
-load("@rules_pkg//pkg:pkg.bzl", "pkg_zip")
+load("@rules_pkg//:pkg.bzl", "pkg_zip")
 
 pkg_zip(
     name = "helloworld",
diff --git a/WORKSPACE b/WORKSPACE
index 9aa5c56..1a5b27e 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -10,7 +10,7 @@ http_archive(
 http_archive(
     name = "rules_pkg",
     sha256 = "5516557c11a0f9a7fa1eda94188c12029ce5ba851451d4481eda43ff2745c0f9",
-    strip_prefix = "rules_pkg-0.2.4",
+    strip_prefix = "rules_pkg-0.2.4/pkg",
     urls = ["https://github.com/bazelbuild/rules_pkg/archive/0.2.4.zip"],
 )
 
@@ -18,6 +18,6 @@ load("@io_bazel_rules_go//go:deps.bzl", "go_rules_dependencies", "go_register_to
 go_rules_dependencies()
 go_register_toolchains()
 
-load("@rules_pkg//pkg:deps.bzl", "rules_pkg_dependencies", "rules_pkg_register_toolchains")
+load("@rules_pkg//:deps.bzl", "rules_pkg_dependencies", "rules_pkg_register_toolchains")
 rules_pkg_dependencies()
 rules_pkg_register_toolchains()

Your suggestion to move the WORKSPACE file to the top-level is a good one; I would also suggest moving the http_archive call for io_bazel_rules_go to rules_pkg_dependencies() as well.