[Buildroot] [PATCH 1/1] package/libnss: fix parallel build failure

[Arnout Vandecappelle]

On 22/09/2021 01:59, Giulio Benetti wrote:
> As explained in the patch itself(pending here[1]), I couldn't reproduce
> the failure but it seems to be right. Basically I'm making not parallel
> every 'nsinstall -R' command that is where it fails.
> 
> [1]: https://bugzilla.mozilla.org/show_bug.cgi?id=1731911
> 
> Fixes:
> http://autobuild.buildroot.net/results/a895ed7aa48edc5cd9ac8bbbd689433a98c9c057/
> 
> Signed-off-by: Giulio Benetti <giulio.benetti at benettiengineering.com>
> ---
>   ...31911-Fix-nsinstall-parallel-failure.patch | 34 +++++++++++++++++++
>   1 file changed, 34 insertions(+)
>   create mode 100644 package/libnss/0001-Bug-1731911-Fix-nsinstall-parallel-failure.patch
> 
> diff --git a/package/libnss/0001-Bug-1731911-Fix-nsinstall-parallel-failure.patch b/package/libnss/0001-Bug-1731911-Fix-nsinstall-parallel-failure.patch
> new file mode 100644
> index 0000000000..7ac340f1ca
> --- /dev/null
> +++ b/package/libnss/0001-Bug-1731911-Fix-nsinstall-parallel-failure.patch
> @@ -0,0 +1,34 @@
> +From 7ba4d627212507f876dc112e89c68e82e1c50188 Mon Sep 17 00:00:00 2001
> +From: Giulio Benetti <giulio.benetti at benettiengineering.com>
> +Date: Wed, 22 Sep 2021 01:40:31 +0200
> +Subject: [PATCH] Bug 1731911 - Fix nsinstall parallel failure
> +
> +Fix nsinstall race condition when building using Makefile with parallel
> +options on. I've end up making $(1) recipe in copy_varlist_into_dir_RULE
> +.NOTPARALLEL. I can't test it that much since it's very very rare, but
> +it seems to be the correct way. This way every copy_varlist_into_dir_RULE
> +called should occur not parallel and I think that this is acceptable
> +since it only create symlinks that takes very few. Further improving is
> +possible of course.
> +
> +Signed-off-by: Giulio Benetti <giulio.benetti at benettiengineering.com>
> +---
> + nss/coreconf/rules.mk | 2 ++
> + 1 file changed, 2 insertions(+)
> +
> +diff --git a/nss/coreconf/rules.mk b/nss/coreconf/rules.mk
> +index dc72e9cef..a341b8385 100644
> +--- a/nss/coreconf/rules.mk
> ++++ b/nss/coreconf/rules.mk
> +@@ -377,6 +377,8 @@ $(3)/%: %
> + 	$$(INSTALL) -m 444 $$^ $(3)
> +
> + $(1): $$(addprefix $(3)/,$$($(2))) | $(3)/d
> ++
> ++.NOTPARALLEL: $(1)

  This doesn't make a whole lot of sense: .NOTPARALLEL is something that applies 
to the Makefile as a whole, not to one specific target. I haven't looked in any 
depth in the libnss build system, but unless it builds recursively, adding this 
is exactly equivalent to adding

.NOTPARALLEL:

anywhere in the Makefiles. This is BTW what we do in Buildroot.

  And in the end, that's the same as calling $(MAKE1) from Buildroot, so 
patching is not really needed.

  If you want to be a little smarter, you will have to manually "unroll" the 
dependency, like:

$(1): | $(3)/d
	$$(foreach tgt,$(2),$(MAKE) $(3)/$$($(tgt)))

(chances are I made some major mistake in this thing).

  Or if it does build recursively, you can probably conditionally add 
.NOTPARALLEL in some smart way.

  Anyway, I've marked this patch as Changed Requested.

  Regards,
  Arnout


> + endif
> + else
> + $(1):
> +--
> +2.25.1
> +
>