Specflow project build is "terminated due to StackOverflowException"

Question

Our Specflow project started to fail the build with "Process is terminated due to StackOverflowException".

I was able to trim down the test project down to just one feature file like this:

Feature: PDBSPCTK Get Availability groups (Avgpad) - Tux

Scenario: Get availability groups JSON
Given I create the following "Avgpad" class and save it as "Avgpad"
Then I verify the "Response_Avgpar" object contains the following data
"""
LARGE JSON DATA
"""

Below is the build output:

Build started at 10:51 AM...
1>------ Build started: Project: TestAutomation, Configuration: Debug Any CPU ------
1>  SpecFlowFeatureFiles: PDBSPCTK\ACSR\Avgpad\Tux\GetAvgpadTux.feature;PDBSPCTK\psRetrieveCCSAccountAndCustomerByUD\Db\RetrieveCCSAccountAndCustomerByUD.feature;PDBSPCTK\psRetrieveCCSAccountAndCustomerByUD\Tux\RetrieveCCSAccountAndCustomerByUD.feature
1>  SpecFlowGeneratedFiles: PDBSPCTK\ACSR\Avgpad\Tux\GetAvgpadTux.feature.cs
1>  SpecFlowGeneratedFiles: PDBSPCTK\psRetrieveCCSAccountAndCustomerByUD\Db\RetrieveCCSAccountAndCustomerByUD.feature.cs
1>  SpecFlowGeneratedFiles: PDBSPCTK\psRetrieveCCSAccountAndCustomerByUD\Tux\RetrieveCCSAccountAndCustomerByUD.feature.cs
1>  SourceRoot value was 'C:\Users\qiuw01\.nuget\packages\;C:\Program Files (x86)\Microsoft Visual Studio\Shared\NuGetPackages\'
1>  SourceRoot value is 'C:\Users\qiuw01\.nuget\packages\;C:\Program Files (x86)\Microsoft Visual Studio\Shared\NuGetPackages\;C:\Users\qiuw01\.nuget\packages\;C:\Program Files (x86)\Microsoft Visual Studio\Shared\NuGetPackages\'
1>  SourceRoot.SourceControl is ''
1>  SourceRoot.MappedPath is 'C:\Users\qiuw01\.nuget\packages\'
1>  SourceRoot.MappedPath is 'C:\Program Files (x86)\Microsoft Visual Studio\Shared\NuGetPackages\'
1>  SourceRoot.SourceLinkUrl is ''
1>C:\Users\qiuw01\.nuget\packages\microsoft.sourcelink.common\1.0.0\build\Microsoft.SourceLink.Common.targets(52,5): warning : Source control information is not available - the generated source link is empty.
1>C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Current\Bin\Roslyn\Microsoft.CSharp.Core.targets(84,5): error : 
1>C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Current\Bin\Roslyn\Microsoft.CSharp.Core.targets(84,5): error : Process is terminated due to StackOverflowException.
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
========== Build completed at 10:51 AM and took 14.314 seconds ==========

Additional information:

1. Stack overflow appears to be related to the size of LARGE JSON DATA. Stack overflow stops to happen once its size is reduced.
2. Stack overflow started to happen after an upstream package introduced dependency on System.Text.Json.

So my question is how indirect dependency on System.Text.Json can cause Specflow to be sensitive to the JSON data size in a feature file?

Answer 1

I can report our findings and solution.

1. Further testing proves that it probably is not a JSON parsing issue, but instead is related to the size limit of embedded multiline string. If the size of the embedded JSON is reduced to less than 335,690 characters, it builds successfully. If one more character is added to make the string 335,690 it hits the StackOverflowException. The issue can be recreated when replacing the embedded JSON with random text up to 335,690 characters. If it remains at 335,689 characters the build succeeds.
2. The build succeeds after the project is converted to SDK style. So the new dependency on System.Text.Json might have triggered some weird interaction of SpecFlow and the old-style project that leads to a StackOverflowError.