Or-tools: google-ortools-native.dll not found

[flyingjones]

What version of OR-tools and what language are you using?
Version: master
Language: C#

Which solver are you using (e.g. CP-SAT, Routing Solver, GLOP, BOP, Gurobi)
Routing Solver

What operating system (Linux, Windows, ...) and version?
Windows Version 1909 Build 18363.535

What did you do?
1) I was using the nuget package for the google or tools with dotnet core 2.2, where everything worked fine.
2) Upgraded to dotnet core 3.1
3) Running my program throws this:
System.TypeInitializationException : The type initializer for 'Google.OrTools.ConstraintSolver.operations_research_constraint_solverPINVOKE' threw an exception. ---- System.TypeInitializationException : The type initializer for 'SWIGExceptionHelper' threw an exception. -------- System.DllNotFoundException : Unable to load DLL 'google-ortools-native' or one of its dependencies: Das angegebene Modul wurde nicht gefunden. (0x8007007E) at Google.OrTools.ConstraintSolver.operations_research_constraint_solverPINVOKE.new_RoutingIndexManager__SWIG_0(Int32 jarg1, Int32 jarg2, Int32 jarg3) at Google.OrTools.ConstraintSolver.RoutingIndexManager..ctor(Int32 num_nodes, Int32 num_vehicles, Int32 depot)

What did you expect to see
No Exception

Anything else we should know about your project / environment
Copying the google-ortools-native.dll from the nuget package to System32 solved the issue

Also this issue did't occour on linux.

[Mizux]

Which TargetFramework did you use in your .csproj ?

[flyingjones]

Wow thank you for the fast reply

I think netcoreapp3.1

My csproj looks like this:

<Project Sdk="Microsoft.NET.Sdk.Web">
    <PropertyGroup>
        <TargetFramework>netcoreapp3.1</TargetFramework>
        <LangVersion>8</LangVersion>
    </PropertyGroup>
    <ItemGroup>
        <PackageReference Include="Google.OrTools" Version="7.4.7247" />
    </ItemGroup>
</Project>

[Mizux]

can you try:

<TargetFramework>netcoreapp2.1</TargetFramework>
<RollForward>LatestMajor</RollForward>

and did you get some warning/errors at build time ?

[flyingjones]

I did not get any warnings from the google or tools namespace.

Since this project is dependent on others, which I already have migrated to dotnet core 3.1,

<TargetFramework>netcoreapp2.1</TargetFramework>
<RollForward>LatestMajor</RollForward>

prevents the whole build.
However I will set up a small standalone without such cross-dependencies and then try it out.
I hope I get this done today or tomorrow.

[Mizux]

For your information the last release 7.4.7247 only contains netstandard2.0 library while the incoming v7.5 release should contains both netstandard2.0 and netstandard2.1 library. I still don't know exactly how it is related to netcoreapp3.1 but it might help (need to setup a vm with only the .Net Core SDK 3.1 to verify).

Also the google-ortools-native.dll is provided by the sub package Google.OrTools.runtime.win-x64.7.4.7247.nupkg so maybe we still have something wrong on window to load this package which contains the library in a native sub-directory

[Mizux]

note: maybe this file is wrong https://github.com/google/or-tools/blob/master/ortools/dotnet/Google.OrTools.runtime.win-x64/Google.OrTools.runtime.win-x64.targets need to test...

[flyingjones]

Turns out cloning my code to another directory and trying it from there made the error go away.

But I seriously don't understand how this can happen, I rebuild and cleaned the solution, even deleted the bin and obj directories, but still in the error persists.
However I tried to reproduce the error in a smaller project but it just wouldn't appear, so I cloned the code "causing" it in another directory and it just worked.
(I even checked cloning it into a directory wich have a longer path, than the original, just to be sure...)

Anyway, thank you very much for your fast replies!

Edit: Not even git clean -xdf fixed it at the old location

Edit2: Seems that I have failed validating the path length... It seems to happen, if the directory path of the project is beyond a certain length

[Mizux]

Glad you was able to fix your issue !

Thank you also to have taken the time to share your feedback with the community !

[gmenaka]

I have the same issue, but my local PC is working. only this error comes when I deploy it to Azure. Do I have to do any extra step?

[Mizux]

@gmenaka see answer in your cross posting -_-