Re: [OE-core] [PATCH v2] layer.conf: fix sanity error for PATH variable in extensible SDK workflow

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

On Sun, 2020-10-11 at 13:26 +0530, Sourabh Banerjee wrote:
> Sanity checker reports following error for the PATH variable,
> when bitbake -e <recipe> command is run in an extensible SDK workspace.
>    PATH contains '.', './' or '' (empty element), which will break the build
> 
> In case of extensible SDK, PATH variable is formed with two consecutive ':'
> as bb.utils.which(d.getVar('PATH'),'bitbake') call returns an empty string.
> 
> This change adds the ':' only if the bb.utils.which(d.getVar('PATH'),'bitbake')
> returns a valid path.
> 
> Signed-off-by: Sourabh Banerjee <sbanerje@codeaurora.org>
> ---
>  meta/conf/layer.conf | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/meta/conf/layer.conf b/meta/conf/layer.conf
> index 38df0f3..75d2ee0 100644
> --- a/meta/conf/layer.conf
> +++ b/meta/conf/layer.conf
> @@ -102,4 +102,12 @@ SSTATE_EXCLUDEDEPS_SYSROOT += "\
>  SSTATE_EXCLUDEDEPS_SYSROOT += ".*->autoconf-archive-native"
>  
>  # We need to keep bitbake tools in PATH
> -PATH := "${@os.path.dirname(bb.utils.which(d.getVar('PATH'),'bitbake'))}:${HOSTTOOLS_DIR}"
> +# The ':' separator is conditionally added only if 'bitbake' is in environment.
> +# In case of extensible SDK, bitbake is not in environment, which results in
> +# two consecutive ':'. Sanity checker reports "empty element" error when it
> +# encounters two consecutive ':' for PATH variable in the extensible SDK.
> +PATH := "\
> +${@os.path.dirname(bb.utils.which(d.getVar('PATH'),'bitbake'))}\
> +${@(':', '')[bb.utils.which(d.getVar('PATH'),'bitbake') is ""]}\
> +${HOSTTOOLS_DIR}\
> +"

I think we need to try and find something a little neater than this.
How about:

# Need to avoid empty path entries
BITBAKEPATH := "${@os.path.dirname(bb.utils.which(d.getVar('PATH'),'bitbake'))}"
PATH := "${@'${BITBAKEPATH}:' if ${BITBAKEPATH} is not ""}${HOSTTOOLS_DIR}"

Cheers,

Richard