#23628 Regression in 2.33: interactive subprocesses are suspended with SIGTTIN Issue created by swhelan091 Describe the bug Starting with Pants 2.33, interactive Terraform deployments hang after entering yes at the apply confirmation prompt.

Terraform prints the plan and prompt normally:
Do you want to perform these actions?
  Only 'yes' will be accepted to approve.

  Enter a value: yes

After entering yes, no deployment operations begin. The Terraform process is suspended in state T:

PID   PPID  PGID  TPGID  STAT  COMMAND
6935  749   6935  6935   S+    pants tf //terraform/stg/api
6998  6935  6998  6935   T     /bin/bash -c ... terraform apply
7046  6998  6998  6935   T     terraform apply

Pants retains foreground terminal ownership (TPGID 6935), while Terraform runs in a separate background process group (PGID 6998). When Terraform attempts to read the confirmation, macOS suspends it with SIGTTIN. The typed yes is echoed but never consumed. The same command works correctly after downgrading to Pants 2.32. Pants version Works: 2.32.0 Broken: 2.33.0, 2.34.0.dev2 Terraform version: 1.12.2. OS macOS 14.7.8 on Apple Silicon Additional info This appears related to PR #23466, introduced in Pants 2.33. It changed child-process setup from setsid() to process_group(0). pantsbuild/pants