Re: [OE-core] [PATCH 3/5] image-artifact-names: Use SOURCE_DATE_EPOCH when making reproducible builds

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Sat, 2021-10-02 at 23:18 +0100, Richard Purdie via lists.openembedded.org
wrote:
> Using DATETIME means the deploy output is not deterministic. Use SDE
> when using reproducible builds since it is consistent for given input data.
> 
> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
> ---
>  meta/classes/image-artifact-names.bbclass | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/meta/classes/image-artifact-names.bbclass b/meta/classes/image-artifact-names.bbclass
> index 3ac8dd731a6..df9e17c6b0f 100644
> --- a/meta/classes/image-artifact-names.bbclass
> +++ b/meta/classes/image-artifact-names.bbclass
> @@ -4,7 +4,7 @@
>  
>  IMAGE_BASENAME ?= "${PN}"
>  IMAGE_VERSION_SUFFIX ?= "-${DATETIME}"
> -IMAGE_VERSION_SUFFIX[vardepsexclude] += "DATETIME"
> +IMAGE_VERSION_SUFFIX[vardepsexclude] += "DATETIME SOURCE_DATE_EPOCH"
>  IMAGE_NAME ?= "${IMAGE_BASENAME}-${MACHINE}${IMAGE_VERSION_SUFFIX}"
>  IMAGE_LINK_NAME ?= "${IMAGE_BASENAME}-${MACHINE}"
>  
> @@ -13,3 +13,10 @@ IMAGE_LINK_NAME ?= "${IMAGE_BASENAME}-${MACHINE}"
>  # by default) followed by additional suffices which describe the format (.ext4,
>  # .ext4.xz, etc.).
>  IMAGE_NAME_SUFFIX ??= ".rootfs"
> +
> +python () {
> +    if bb.data.inherits_class('reproducible_build', d):
> +        import datetime
> +        d.setVar("IMAGE_VERSION_SUFFIX", "-" + datetime.datetime.fromtimestamp(int(d.getVar("SOURCE_DATE_EPOCH")), datetime.timezone.utc).strftime('%Y%m%d%H%M%S'))
> +        d.setVarFlag("IMAGE_VERSION_SUFFIX", "vardepvalue", "")
> +}

This patch is incorrect. It breaks images as they have noexec do_unpack tasks.

Cheers,

Richard