#21755·mono

NameResolutionFailure for any url in proot-distro

Author: BokerBobCreated Mar 24, 2024Updated Aug 6, 2026

DNS problems in proot

I have a permanent issue with the DNS for Mono installed in termux proot-distro Linux (tried Debian, Ubuntu, Arch). Mono package in Termux resolves hostnames without problems. Debian terminal ping and dig returns data successfully for http and https. /etc/resolve.conf contains 8.8.8.8 and 8.8.4.4. I tried to reinstall termux - the same behaviour. Android Private DNS on/off doesn't help. LTE/WiFi - the same behaviour.

Steps to Reproduce

  1. Install Debian using this tutorial https://ivonblog.com/en-us/posts/termux-proot-distro-debian/.
  2. Install Mono https://www.mono-project.com/download/stable/#download-lin-debian.
  3. Run csharp -e 'new System.Net.WebClient ().DownloadString ("https://www.nuget.org")'.

Current Behavior

System.Net.WebException: Error: NameResolutionFailure

Screenshot_20240324_123016_TermuxX11

Expected Behavior

Returns response.

On which platforms did you notice this

[ ] macOS [x] Linux [ ] Windows

Version Used:

Samsung S24 Ultra noroot Termux & Termux11 proot-distro XFCE4 Debian 12 Mono 6.12.0 Stable

Stacktrace

user@localhost:~/Desktop$ csharp -e 'new System.Net.WebClient ().DownloadString ("https://www.nuget.org")'
System.Net.WebException: Error: NameResolutionFailure
  at System.Net.WebConnection.Connect (System.Net.WebOperation operation, System.Threading.CancellationToken cancellationToken) [0x00044] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebConnection.InitConnection (System.Net.WebOperation operation, System.Threading.CancellationToken cancellationToken) [0x000cc] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebOperation.Run () [0x0009a] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebCompletionSource`1[T].WaitForCompletion () [0x00094] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.HttpWebRequest.RunWithTimeoutWorker[T] (System.Threading.Tasks.Task`1[TResult] workerTask, System.Int32 timeout, System.Action abort, System.Func`1[TResult] aborted, System.Threading.CancellationTokenSource cts) [0x000f8] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.HttpWebRequest.GetResponse () [0x00016] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebClient.GetWebResponse (System.Net.WebRequest request) [0x00000] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebClient.DownloadBits (System.Net.WebRequest request, System.IO.Stream writeStream) [0x000e6] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebClient.DownloadDataInternal (System.Uri address, System.Net.WebRequest& request) [0x00061] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebClient.DownloadString (System.Uri address) [0x00011] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at System.Net.WebClient.DownloadString (System.String address) [0x00008] in <a8a996a78a804d888710c9e2575d78c8>:0 
  at <InteractiveExpressionClass>.Host (System.Object& $retval) [0x00006] in <b41073e115174b6e92a16600b2aa6683>:0 
  at Mono.CSharp.Evaluator.Evaluate (System.String input, System.Object& result, System.Boolean& result_set) [0x00038] in <fadecaf77ec64f2086c203167cec7602>:0 
  at Mono.CSharpShell.Evaluate (System.String input) [0x00000] in <3570010a78af4689adfde4b716a7f7c2>:0