Re: [PATCH 2/3] golang/xenlight: init xenlight go module

[George Dunlap <George.Dunlap@xxxxxxxxxx>]

> On May 12, 2020, at 6:30 PM, George Dunlap <george.dunlap@xxxxxxxxxx> wrote:
> 
>> 
>> On May 12, 2020, at 4:06 PM, Nick Rosbrook <rosbrookn@xxxxxxxxx> wrote:
>> 
>> [CAUTION - EXTERNAL EMAIL] DO NOT reply, click links, or open attachments 
>> unless you have verified the sender and know the content is safe.
>> 
>> On Tue, May 12, 2020 at 10:36 AM George Dunlap <George.Dunlap@xxxxxxxxxx> 
>> wrote:
>>> 
>>> 
>>> 
>>>> On Apr 30, 2020, at 10:39 PM, Nick Rosbrook <rosbrookn@xxxxxxxxx> wrote:
>>>> 
>>>> Initialize the xenlight Go module using the xenbits git-http URL,
>>>> xenbits.xen.org/git-http/xen.git/tools/golang/xenlight, and update the
>>>> XEN_GOCODE_URL variable in tools/Rules.mk accordingly.
>>>> 
>>>> Signed-off-by: Nick Rosbrook <rosbrookn@xxxxxxxxxxxx>
>>>> ---
>>>> tools/Rules.mk               | 2 +-
>>>> tools/golang/xenlight/go.mod | 1 +
>>>> 2 files changed, 2 insertions(+), 1 deletion(-)
>>>> create mode 100644 tools/golang/xenlight/go.mod
>>>> 
>>>> diff --git a/tools/Rules.mk b/tools/Rules.mk
>>>> index 5b8cf748ad..ca33cc7b31 100644
>>>> --- a/tools/Rules.mk
>>>> +++ b/tools/Rules.mk
>>>> @@ -36,7 +36,7 @@ debug ?= y
>>>> debug_symbols ?= $(debug)
>>>> 
>>>> XEN_GOPATH        = $(XEN_ROOT)/tools/golang
>>>> -XEN_GOCODE_URL    = golang.xenproject.org
>>>> +XEN_GOCODE_URL    = xenbits.xen.org/git-http/xen.git/tools/golang
>>> 
>>> The primary effect of this will be to install the code in 
>>> $PREFIX/share/gocode/xenbits.xen.org/git-http/xen.git/tools/golang/xenlight 
>>> when making debballs or doing `make install`.
>>> 
>>> I don’t immediately see the advantage of that, particularly if we’re still 
>>> thinking about having a “prettier” path at some point in the future.  What 
>>> was your thinking here?
>> 
>> With the module being defined as `xenbits.xen.org/...`, the `build`
>> Make target will fail as-is for a module-aware version of go (because
>> it cannot find a module named `golang.xenproject.org/xenlight`). So,
>> the reason for this change is to preserve the existing functionality
>> of that Make target. Changing XEN_GOCODE_URL seemed like the correct
>> change, but I'm open to suggestions.
> 
> Oh.  But no, that’s not at all what we want.
> 
> The whole point of running ‘go build’ is to make sure that *the code we just 
> copied* — the code right now in our own local tree, perhaps which was just 
> generated — actually compiles.
> 
> It looks like when we add the `go.mod` further up the tree, it makes `go 
> build` ignore the GOPATH environment variable we’re giving it, which causes 
> the build failure.  But your “fix” doesn’t make it use the in-tree go code 
> again; instead it looks like it causes `go build` command to go and fetch the 
> most recent `master` version from xenbits, ignoring the go code in the tree 
> completely. :-)

OK, so actually what you want to do is replace the `go install -x 
$OTHER_PLACE_WE_JUST_COPIED_THE_FILES` with `go build -x` in the Makefile.

 -George