How to access Ivy directly, i.e. access dependency reports or execute Ivy commands?

问题

SBT uses Ivy under the hood for dependencies. Ivy can generate lots of dependency reports. How can I get access to that via SBT?

In general, if I want to use an Ivy command via SBT, how can I do it? Can I generate a POM from the SBT dependencies?

UPDATE: My goal is to debug and manually fine tune problems, not to be part of any automated tasks

UPDATE 2: To debug, I'd like to see the whole transitive dependency chain, not just the top level dependencies.

回答1:

There are several options when debugging dependencies.

Using sbt-dependency-graph

You can use whatDependsOn <organization> <module> <revision> command to see where the dependency is used.

For example I have a transitive dependency to org.apache.httpcomponents:httpcore:4.0.1. To see what includes it I can use whatDependsOn.

[play-slick-advanced] $ whatDependsOn org.apache.httpcomponents httpcore 4.0.1
[info] org.apache.httpcomponents:httpcore:4.0.1
[info]   +-oauth.signpost:signpost-commonshttp4:1.2.1.2
[info]   | +-com.typesafe.play:play_2.10:2.2.0
[info]   |   +-com.typesafe.play:play-java_2.10:2.2.0
[info]   |   | +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]   |   | 
[info]   |   +-com.typesafe.play:play-jdbc_2.10:2.2.0
[info]   |   | +-com.typesafe.play:play-slick_2.10:0.5.0.8 [S]
[info]   |   |   +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]   |   |   +-org.virtuslab:unicorn_2.10:0.4 [S]
[info]   |   |     +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]   |   |     
[info]   |   +-com.typesafe.play:play-slick_2.10:0.5.0.8 [S]
[info]   |   | +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]   |   | +-org.virtuslab:unicorn_2.10:0.4 [S]
[info]   |   |   +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]   |   |   
[info]   |   +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]   |   
[info]   +-org.apache.httpcomponents:httpclient:4.0.1
[info]     +-oauth.signpost:signpost-commonshttp4:1.2.1.2
[info]       +-com.typesafe.play:play_2.10:2.2.0
[info]         +-com.typesafe.play:play-java_2.10:2.2.0
[info]         | +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]         | 
[info]         +-com.typesafe.play:play-jdbc_2.10:2.2.0
[info]         | +-com.typesafe.play:play-slick_2.10:0.5.0.8 [S]
[info]         |   +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]         |   +-org.virtuslab:unicorn_2.10:0.4 [S]
[info]         |     +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]         |     
[info]         +-com.typesafe.play:play-slick_2.10:0.5.0.8 [S]
[info]         | +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]         | +-org.virtuslab:unicorn_2.10:0.4 [S]
[info]         |   +-default:play-slick-advanced_2.10:1.0.1 [S]
[info]         |   
[info]         +-default:play-slick-advanced_2.10:1.0.1 [S]

Just using sbt

I think the fact that the reports are produced is a cool and underestimated feature. They are generated in the target/resolution-cache/reports directory, after the update task.

This is step by step guide on how to use them.

Clean project

Run `update` and go to `target/resolution-cache/reports`

Open any of the XML files with Firefox

This part is a bit tricky, for some reason some browsers will render the correct report, and some will read the file as an XML file. Not sure why it is like that, but for sure Firefox works well. Doesn't really matter which file you'll open as you can switch between them using tabs in the rendered page.