Pub upgrade fails with some dependencies

[DartBot]

Originally opened as dart-lang/sdk#21259

This issue was originally filed by defave...@gmail.com

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What steps will reproduce the problem?

1. Create a simple project
2. Add those dependencies (I've cleaned the list in order to find the minimum set):
     paper_elements: any
     di: ">=3.1.0 <4.0.0"
     collection: any
3. do a pub upgrade

What is the expected output? What do you see instead?
I expect a resolved dependency message but I get this error:
Pub upgrade failed, [69] Resolving dependencies...
Connection closed before full header was received

What version of the product are you using?
1.6.0

On what operating system?
Linux Mint 0.17

What browser (if applicable)?
n/a

Please provide any additional information below.
Adding this override solves the issue:
dependency_overrides:
  args: any

[DartBot]

<img src="https://avatars.githubusercontent.com/u/2156198?v=3" align="left" width="48" height="48"hspace="10"> Comment by kasperl

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Added Area-Pub, Triaged labels.

[DartBot]

<img src="https://avatars.githubusercontent.com/u/188?v=3" align="left" width="48" height="48"hspace="10"> Comment by nex3

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Please include the output when you run "pub upgrade --verbose".

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Added NeedsInfo label.

[DartBot]

This comment was originally written by defav...@gmail.com

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Looks like the Solver is looping, I had to stop it after a while.
In attachment the output.

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Attachment:
pub-output.txt.zip (262.16 KB)

[DartBot]

<img src="https://avatars.githubusercontent.com/u/188?v=3" align="left" width="48" height="48"hspace="10"> Comment by nex3

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It looks like these are incompatible constraints; in particular, it seems like the collection package has disjoint constraints, although I'm not sure where they're coming from.

I'm merging this into 17429, which is tracking better reporting for solver failures.

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Added Duplicate label.
Marked as being merged into #912.