I'd love to go the first route, but unfortunately Google is only making the Android libraries available via a repository that is downloaded (and updated) via the Android SDK. So they are not visible on Maven Central and Maven Central obviously couldn't vet them.
The second option would work, but I'd argue that it lends itself to convention clouding the expected behaviour as you'd need a map to know how each packaging type impacted the behaviour of unspecified dependency types. UNLESS the convention was that all dependencies with no type information get the packaging type of their project. But this would massively break existing build (think of all the war POMs). [image: photo] *William Ferguson* Founder and CEO, XandarMob m:+61 425 716 870 | e:william.fergu...@xandar.com.au | w:https://wylas-timing.com http://lexathon.com <http://wylas-timing.com http://lexathon.com> ᐧ On Fri, Dec 19, 2014 at 10:54 PM, Igor Fedorenko <i...@ifedorenko.com> wrote: > > Ok, I understand the problem now, but I don't think forcing everything > to explicitly state dependency type is the right solution here. > "Convention over configuration" is one of fundamental Maven principals, > and by convention dependencies are assumed to have type=jar. > > I see two possible ways to improve here. > > I think Maven Central can be more strict about artifacts it accepts. It > should not be too difficult to validate all dependencies are present in > Central, for example, or present in Central or <repositories> configured > in pom.xml. > > Alternatively, we can also extend Maven to support different conventions > for different packaging types. This will be much more work and I didn't > think about implications of this change, but, in theory, it should be > possible to assume dependencies of artifacts with packaging=aar use > dependency type=aar by default. > > -- > Regards, > Igor > > > On 2014-12-17, 17:20, William Ferguson wrote: > >> Sorry Igor, I see now I omitted a chunk of context. >> >> The reason for the error is that this component : >> >> <dependency> >> <groupId>com.android.support</groupId> >> <artifactId>support-v13</artifactId> >> <version>21.0.2</version> >> <type>aar</type> >> </dependency> >> >> has a dependency upon >> >> <dependency> >> <groupId>com.android.support</groupId> >> <artifactId>support-v4</artifactId> >> <version>21.0.2</version> >> <type>aar</type> >> </dependency> >> >> But when the Android team packaged up support-v13, they declared the >> dependency on support-v4 as: >> <dependency> >> <groupId>com.android.support</groupId> >> <artifactId>support-v4</artifactId> >> <version>21.0.2</version> >> </dependency> >> >> which is a valid definition syntactically, may well be valid inside the >> Android dev team, and is parsed by the Android Gradle plugin (which makes >> gross assumptions about artifact type). >> >> But from a standard Maven perspective, that dependency definition is not >> valid. Which is why tools like the dependency-plugin (and anything that >> introspects deps) with fail with that dependency definition. >> >> We are pushing back on the Android guys to generate Maven POMs that are >> consumable by everyone, but the fact that the syntax allows them to >> generate an underspecified dependency could be eliminated. I think this is >> especially important as Maven is used by a wider and wider community. >> While >> it stemmed from Java builds, it is now used much more widely than pure >> Java >> libraries. >> >> William >> >> >> ᐧ >> >> On Tue, Dec 9, 2014 at 2:39 AM, Igor Fedorenko <i...@ifedorenko.com> >> wrote: >> >>> >>> I am not sure I follow. Can you explain what actually happens and how >>> forcing <type> element for all projects dependencies is expected to help >>> the problem? >>> >>> -- >>> Regards, >>> Igor >>> >>> >>> On 2014-12-07, 19:25, William Ferguson wrote: >>> >>> ## Cross posting to Maven Dev list >>>> >>>> One solution to this would be to change the POM specification to require >>>> the type element for dependencies. >>>> That would allow Maven and MavenCentral to immediately fail POMs based >>>> upon dependencies that are missing the type element. >>>> >>>> Yes, it goes against convention over configuration, but Maven is now >>>> used by many more build types than just plain Java builds so maybe we >>>> need to consider that the convention is no longer to assume jar >>>> dependencies. >>>> >>>> I would rather require a little more configuration to ensure that builds >>>> are more deterministic. >>>> If we want to shrink the size of the POM then the new POM format is a >>>> better solution. >>>> >>>> William >>>> >>>> >>>> On Thursday, December 4, 2014 1:47:33 AM UTC+10, Andreas Schildbach >>>> wrote: >>>> >>>> I'm using maven-android-plugin 4.0.0 with Maven 3.0.5. I've got >>>> troubles declaring an aar dependency. Here is the pom.xml >>>> declaration: >>>> >>>> | >>>> <dependency> >>>> <groupId>com.android.support</groupId> >>>> <artifactId>support-v13</artifactId> >>>> <version>21.0.2</version> >>>> <type>aar</type> >>>> </dependency> >>>> | >>>> >>>> Just about any Maven command, even "mvn dependency:tree" yields: >>>> >>>> [ERROR] Failed to execute goal on project wallet: Could not resolve >>>> dependencies for project de.schildbach.wallet:wallet: >>>> apk:4.13-test: >>>> Failure to find com.android.support:support-v4:jar:21.0.2 in >>>> file:///home/aschildbach/dev/android-sdk/extras/android/ >>>> m2repository >>>> was cached in the local repository, resolution will not be >>>> reattempted until the update interval of android-support has >>>> elapsed >>>> or updates are forced -> [Help 1] >>>> >>>> Where does that .jar type in the error message stem from? I >>>> declared >>>> aar. >>>> >>>> >>>> >>>> >>>> --------------------------------------------------------------------- >>>> To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org >>>> For additional commands, e-mail: dev-h...@maven.apache.org >>>> >>>> >>>> --------------------------------------------------------------------- >>> To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org >>> For additional commands, e-mail: dev-h...@maven.apache.org >>> >>> >>> >> > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@maven.apache.org > For additional commands, e-mail: dev-h...@maven.apache.org > >
