Bug: DNS Resolving Issue in Deno 2.1.5+ on Windows 11

[ghostzero]

Version:
Bug begins at Deno 2.1.5

OS:

• Windows 11 23H2 (OS Build 22631.4751) – Issue occurs
• Ubuntu 24.04 LTS – No issue observed

Description:
After upgrading to the latest version of Deno (v2.1.9), the CLI prints the following error message when running commands that uses DNS like axios:

could not parse an IP from hosts file

Despite this message, DNS resolution appears to work correctly, but there is a noticeable degradation in performance. The issue does not occur on Linux (Ubuntu 24.04 LTS), where performance remains normal and no such error message is printed.

Somethimes this message is also posted multiple times.

Potential Cause:
This issue might be related to recent DNS resolving changes introduced in #27572, based on the changelog on GitHub.

Actual Behavior:

• The CLI prints could not parse an IP from hosts file on Windows 11.
• Performance is degraded on Windows but remains normal on Linux.
• Command executes successfully, while execution time increase to +20 seconds.

Expected Behavior:

• No unexpected error messages should appear for DNS issues.
• CLI performance should not degrade after updating to 2.1.5.
• Command executes successfully.

Steps to Reproduce:

1. Install or update to Deno 2.1.5 on Windows 11 23H2.
2. Run any Deno CLI command that requires dns resolution (e.g., fetching something with axios).
3. Observe the error message:

   could not parse an IP from hosts file
   

4. Compare the same command execution on Ubuntu 24.04 LTS (no error message and no performance degradation).