Wrong error message when failing to resolve packages.

[matthid]

While testing I found the following edge case:
Consider the following paket.dependencies

redirects: on
source https://nuget.org/api/v2

//Build
nuget FAKE == 3.36.0
nuget Yaaf.AdvancedBuilding == 0.8.0
nuget FSharp.Formatting == 2.11.1-alpha1
//nuget FSharp.Compiler.Service == 1.3.1.2
//nuget FSharpVSPowerTools.Core == 1.9.0

Paket will complain with

Paket version 2.14.1.0                           
Resolving packages for group Main:               
 - FAKE 3.36.0                                   
 - FSharp.Formatting 2.11.1-alpha1               
 - Yaaf.AdvancedBuilding 0.8.0                   
 - FSharp.Compiler.Service 1.3.1.2               
 - FSharp.Compiler.Service 1.3.1                 
 - FSharp.Compiler.Service 0.0.90                
Paket failed with:                               

Error in resolution.                             
  Resolved:                                      
   - FAKE == 3.36.0                              
   - FSharp.Formatting == 2.11.1-alpha1          
   - Yaaf.AdvancedBuilding == 0.8.0              
   - FSharp.Compiler.Service >= 0.0.90 < 1.4     
  Could not resolve package FAKE:                
   - Dependencies file requested == 3.36.0       
   - Yaaf.AdvancedBuilding 0.8.0 requested 4.0.2 
   - Yaaf.AdvancedBuilding 0.8.0 requested 4.0.2 
 Please try to relax some conditions.            

This is wrong, because we specified (and forced) the FAKE version.
Instead Paket failed to resolve a FSharpVSPowerTools.Core because
Yaaf.AdvancedBuilding requires exactly 1.8 while FSharp.Formatting
requires exactly 1.9.

In fact, the following works as expected:

redirects: on
source https://nuget.org/api/v2

//Build
nuget FAKE == 3.36.0
nuget Yaaf.AdvancedBuilding == 0.8.0
nuget FSharp.Formatting == 2.11.1-alpha1
//nuget FSharp.Compiler.Service == 1.3.1.2
nuget FSharpVSPowerTools.Core == 1.9.0

An other interesting case is

redirects: on
source https://nuget.org/api/v2

//Build
nuget FAKE == 3.36.0
nuget Yaaf.AdvancedBuilding == 0.8.0
nuget FSharp.Formatting == 2.11.1-alpha1
nuget FSharp.Compiler.Service == 1.3.1.2
//nuget FSharpVSPowerTools.Core == 1.9.0

Because in this case Paket will print the correct error message:

Paket version 2.14.1.0                                 
Resolving packages for group Main:                     
 - FAKE 3.36.0                                         
 - FSharp.Formatting 2.11.1-alpha1                     
 - FSharp.Compiler.Service 1.3.1.2                     
 - Yaaf.AdvancedBuilding 0.8.0                         
Paket failed with:                                     

Error in resolution.                                   
  Resolved:                                            
   - FAKE == 3.36.0                                    
   - FSharp.Formatting == 2.11.1-alpha1                
   - FSharp.Compiler.Service == 1.3.1.2                
   - Yaaf.AdvancedBuilding == 0.8.0                    
   - FSharp.Compiler.Service >= 0.0.90 < 1.4           
   - FAKE 4.0.2                                        
   - FSharp.Formatting 2.10.0                          
  Could not resolve package FSharpVSPowerTools.Core:   
   - FSharp.Formatting 2.11.1-alpha1 requested 1.9.0   
   - Yaaf.AdvancedBuilding 0.8.0 requested 1.8.0       
   - FSharp.Formatting 2.11.1-alpha1 requested 1.9.0   
 Please try to relax some conditions.                  

To be clear: The problem is not that paket is failing...
Just the error message is incorrect.

[forki]

wow interesting case. Will look into this tomorrow during train ride.

[forki]

could you please try again?

[matthid]

Yes and in fact after reporting I found a very similar edge case where it was a real bug (where paket failed when it shouldn't) which is now gone as well, very nice! As always thanks for the fast release 👍

[forki]

Mhm, could you please describe the case? I'm a bit worried when we fixed
something other than error messages here. At least we should create an
regression test to track that constellation.
On Oct 17, 2015 10:35 PM, "Matthias Dittrich" notifications@github.com
wrote:

Yes and in fact after reporting I found a very similar edge case where it
was a real bug (where paket failed when it shouldn't) which is now gone as
well, very nice! As always thanks for the fast release [image: 👍]

—
Reply to this email directly or view it on GitHub
#1142 (comment).

[matthid]

Sure... Consider the following paket.dependencies:

$cat paket.dependencies
redirects: on
source https://nuget.org/api/v2

nuget FAKE == 4.7.0
nuget FSharp.Compiler.Service == 1.4.0.6
nuget FSharp.Formatting == 2.11.1-alpha1
nuget FSharpVSPowerTools.Core == 2.1.0
nuget Yaaf.AdvancedBuilding == 0.5.5

paket.exe update fails with 2.14.2

$paket.exe update
Paket version 2.14.2.0
Resolving packages for group Main:
 - FAKE 4.7.0
 - FSharp.Formatting 2.11.1-alpha1
Paket failed with:
        Could not find compatible versions for top level dependency:
     "FSharpVSPowerTools.Core == 2.1.0 (from c:\Projects\paket.test\paket.dependencies)
     FSharpVSPowerTools.Core 1.9.0 (from FSharp.Formatting 2.11.1-alpha1)"
   Available versions:
     - 2.1.0
     - 2.0.0-beta
     - 1.9.0
     - 1.8.0
     - 1.7.0
     - 1.6.1
     - 1.6.0
     - 1.5.0
     - 1.4.0
     - 1.3.1
     - 1.3.0
     - 1.2.6
     - 1.2.5
     - 1.2.1
   Try to relax the dependency or allow prereleases.                                     

But works with latest/current/2.15.1:

$paket.exe update
Paket version 2.15.1.0
Resolving packages for group Main:
 - FAKE 4.7.0
 - FSharp.Formatting 2.11.1-alpha1
 - FSharpVSPowerTools.Core 2.1.0
 - FSharp.Compiler.Service 1.4.0.6
 - Yaaf.AdvancedBuilding 0.5.5
Locked version resolution written to c:\Projects\paket.test\paket.lock
4 seconds - ready.

I think the current behavior is correct as there is basically nothing to resolve (I resolved everything by hand).