Summary

On Windows, starting a WSL (Ubuntu) session in Warp never completes — it hangs indefinitely at "Starting shell ...". This happens both when launching Ubuntu directly from the new-tab (+) shell picker and when entering WSL as a subshell from PowerShell (wsl). In the subshell case, Warp''s Warpify bootstrap is additionally printed to the terminal as raw text instead of executing. WSL was Warpifiable before, so this appears to be a regression.

Problem

Warp cannot bring up an interactive WSL session. The block stays labeled "in pwsh" and the pane shows "Starting shell ..." indefinitely; the native launch surfaces a "Seems like your shell is taking a while to start... / Show initialization block" banner. In the subshell path, the InitSubshell / InitShell bootstrap ([ -z $WARP_BOOTSTRAPPED ] && ... printf OSC/DCS one-liners, and eval of the export WARP_HONOR_PS1=1; ... WARP_USING_WINDOWS_CON_PTY ... setup) is echoed verbatim rather than consumed, so Warpify never completes.
WSL itself is healthy and is not the cause: an interactive bash that sources the full ~/.bashrc outside Warp (wsl bash -ic 'echo READY') returns instantly, and non-interactive wsl bash -c works normally. The failure is specific to Warp''s WSL session startup path. Removing a SourcedRcFileForWarp auto-Warpify snippet from ~/.bashrc did not help.

Expected behavior

Launching Ubuntu (from the + picker or via wsl in PowerShell) should start an interactive WSL session with full Warp features, without hanging and without printing the bootstrap script.

Actual behavior

• Native + -> Ubuntu (bash): pane hangs at "Starting shell ..." with a "Seems like your shell is taking a while to start... / Show initialization block" banner; the session never becomes interactive.
• wsl from PowerShell: Warp prints its Warpify bootstrap one-liners as raw text and hangs at "Starting shell ..."; block stays tagged "in pwsh".
• Adding the documented auto-Warpify SourcedRcFileForWarp snippet to the end of ~/.bashrc made Warp respond with the InitShell setup script, but that was also echoed as raw text and the session still hung; removing it did not change the hang.

Reproduction steps or desired workflow

1. On Windows 11 with WSL2 (Ubuntu), open Warp (default shell PowerShell/pwsh).
2. Use the new-tab (+) shell picker and choose Ubuntu -> pane hangs at "Starting shell ...".
3. Or, in a PowerShell tab run wsl -> Warp prints its Warpify bootstrap one-liners as raw text and hangs at "Starting shell ...".

Artifacts

Screenshot 1: WSL launched from PowerShell (wsl): Warp''s InitSubshell/InitShell bootstrap one-liners printed as raw text, block still tagged "in pwsh", pane stuck at "Starting shell ...".

Screenshot 2: Ubuntu launched natively from the new-tab (+) picker (bash): "Seems like your shell is taking a while to start... / Show initialization block" banner with the pane stuck at "Starting shell ...".

Warp version

v0.2026.07.01.09.21.stable_01

Operating system

Windows 11 Pro, build 26200 (10.0.26200). WSL 2.9.3.0 (kernel 6.18), distro Ubuntu on WSL2.