Usman,
Thanks for supplying the image ... with that I could diagnose the
problem. In the final analysis, the onDowngrade: feature just does not
work[1]. I haven't had a `downgrade` use case in my own work flow, so I
did not notice that it wasn't working and the test cases that I do have
are obviously faulty.
Along the way, I discovered that in the Moose image, there is a custom
MetacelloPlatform class installed (GTMetacelloPlatform) that is not
compatible with the Scripting API. With that class installed, the
scripting API will not work. I was able to install the proper platform
class myself, but it requires manual intervention ...
Also, it turns out the PetitParser 1.10 is the version that is installed
and your new version 1.51 is not technically a downgrade ... I think
that the version needs to be named 1.5.1 to be a downgrade ... I changed
that as well and that's when I was able determine that onDowngrade:
wasn't functioning correctly.
Basically, the code said "go ahead and downgrade" but when it came time
to actually load the packages, Metacello went ahead with it's standard
algorithm of only loading newer versions of each package.
I plan to take a crack at fixing this bug this weekend ... and will let
you when I have a fix.
Dale
[1] https://github.com/dalehenrich/metacello-work/issues/317
On 1/8/15 12:32 AM, Usman Bhatti wrote:
On Wed, Jan 7, 2015 at 8:25 PM, Dale Henrichs
<[email protected]
<mailto:[email protected]>> wrote:
Usman,
No, I appreciate your patience:) If creating your own
configuration works for you then that is a good route to go...
Sharing your image will make it much easier for me to get the
bottom of this (on my own schedule:), so please send me a link for
accessing your image and I'll dig into this in more detail when I
have time ...
Here is the image.
https://dl.dropboxusercontent.com/u/11804892/downgrade-with-metacello.zip
You just need to execute the script in the workspace/playground to
reproduce the problem (i.e. launching the directive to load PP 1.51
and that not happening).
If you find yourself stuck and needing the `downgrade directive`
again, I'll bump up the priority ...
I can still wait till next week. If you could have a look by then,
it'll be great.
tx.
Usman
Dale
On 01/07/2015 09:19 AM, Usman Bhatti wrote:
On Tue, Jan 6, 2015 at 6:56 PM, Dale Henrichs
<[email protected]
<mailto:[email protected]>> wrote:
On 1/6/15 7:16 AM, Usman Bhatti wrote:
Dale,
I couldn't make it work with the upgraded Metacello and the
script you provided.
Steps I did:
1. Download moose image:
https://ci.inria.fr/moose/job/moose-5.0/
2. Update my Metacello to the 'full' version:
Metacello new
baseline: 'Metacello';
repository:
'github://dalehenrich/metacello-work:master/repository';
get.
Metacello new
baseline: 'Metacello';
repository:
'github://dalehenrich/metacello-work:master/repository';
onConflict: [:ex | ex allow];
load
3. File in the ConfigurationOfDummyParser (see the first
message in the thread).
4. Run this script to downgrade to PetitParser version 1.51
Metacello new
configuration: 'DummyParser';
version: '1.0';
repository: '???';
onDowngradeUseIncoming: #('PetitParser');
load.
The desired version is still not loaded, am I missing
something here?
Good question, I don't have a lot of time today to spend time
trying to reproduce your problem, but if you send me a copy
of the Transcript produced while doing the load I might be
able to spot the problem ...
It looks to me that the downgrade command is not working.
Whenever I point to the version preceding the one loaded, the
packages are not fetched.
I am attaching here two files.
The first (Transcript-PP151) is the output of the transcript as
you asked. You can see that PetitParser packages as defined by
the version 1.51 are not fetched. All that is loaded is Glamour
because the version 1.51 of PetitParser loads the latest packages
of Glamour. The load works because it is an upgrade from the
current version of Glamour which is a stable.
When I saw that only Glamour packages are loaded, I thought of
testing Glamour downgrade too to see if the problem is specific
to PetitParser. You can see the result in the second file
(Transcript-downgrade-glamour). No packages of Glamour are
fetched because the configuration tries to downgrade it (stable
is more recent than 3.0.0 which I try to load).
In my opinion, downgrade is not working as required. If you want
I can share my image thru dropbox so that you can have a look to
see what might be wrong.
regards,
A question: I always use Metacello with ConfigOf and have
never used the scripting API myself or saw it being used
elsewhere.
Can you provide a link that describes the use cases for
both: ConfigOf vs. Scripting API?
I've noticed the same thing:)
My "elevator pitch" for the script api goes like this:
1. The scripting api maintains a registry of the actual
project versions loaded into the image,
making #currentVersion obsolete. #currentVersion is bad
because it does a calculation of
the current version that can be very slow and sometimes
completely incorrect.
2. The old api has rules that it follows when loading
projects (i.e., newer projects always win) and
there is no mechanism for altering those rules. The
scripting api provides mechanisms for
for bending those rules to fit your needs ... like
allowing a downgrade of a project.
Part of the reason that people haven't changed has to do with
how incredibly difficult it is to change the existing
inertia. Another part of it is that I continue to support the
old way of doing things, so there is no explicit motivation
to change.
If you look back 2-3 years in the archives of the Metacello
mailing list[1] you should be able to find a number of posts
where I make a more detailed cases for the scripting api:)
At the end of the day, it isn't important to me to "get
people to use the scripting api," as I said, I continue to
support using the old api. I figure that when enough people
start asking questions about how to "bend the Metacello
rules" that folks will begin to use the "new" scripting api:)
So, what I learn is that I am trying to bend the rules of
Metacello which is a rare use case :). I am thinking of avoiding
this downgrading altogether by forking to create my own ConfigOf
that loads the correct versions. Downgrading might be an
anti-pattern.
Thank you for your patient so far :)
regards.
Dale
[1] https://groups.google.com/forum/#!forum/metacello
<https://groups.google.com/forum/#%21forum/metacello>
