LGTM constantly fail

Hi,
I have an issue with LGTM analysis. Since a month ago, the C# analysis failed to build the merge : https://lgtm.com/projects/g/ycrumeyrolle/Jwt/logs/rev/pr-4b6666d2796e6fb7339e82b130d320046d50adf5/lang:csharp/stage:Build%20merge_583cf92d36688a057e308018af0890d983dd7565
There is no logs available, the only information is Failed with bad exit code during 'Extraction'
Someone know what the problem?
@lgtmco