GeezerVison

Pretty sure the convention IS to use /tmp/.X11-unix/X as the socket path. This PR would just break things.

tempfile.gettempdir() reads TMPDIR, TEMP and TMP. Debian's libpam-tmpdir sets TMPDIR=/tmp/user/<uid> for every login, so this PR would look for /tmp/user/1000/.X11-unix/X0, which doesn't exist. The abstract socket fallback would also break, because this PR builds that name from the same path. The server listens on the abstract name @/tmp/.X11-unix/X0, which is also fixed, so both lookups would miss. Every other X client on that machine would still connect fine.

The one real exception is macOS XQuartz, whose socket lives under /private/tmp/com.apple.launchd.*. Though that path comes through DISPLAY, not TMPDIR.

That is a very valid point. While the goal here is to support Termux on Android (where X servers must place their sockets under $TMPDIR mainly because standard /tmp is inaccessible), relying unconditionally on tempfile.gettempdir() or TMPDIR across all environments is an overly broad fix.

To solve this without causing regressions on standard Linux, a few alternative approaches were considered:

• Socket connection fallback (trying /tmp first, then $TMPDIR):

  • Automatically probing fallback directories upon failure carries a security risk of connecting to an unintended socket and exposing X11 authentication data.

• Checking sys.platform == 'android':

  • Since 'android' was only introduced in Python 3.13, supporting Python < 3.13 would require a redundant fallback to TERMUX_VERSION anyway. Moreover, given how narrow the X11 ecosystem on Android is, rather than casting a wide net with a dual check, it is much cleaner and safer to just target Termux directly with a single check.

This narrows the practical solutions down to two main options:

1. Keep the project strictly platform-agnostic: Introduce a dedicated environment variable

• For example, allowing users to explicitly override the socket directory via something like PYTHON_XLIB_SOCKET_DIR.
• This avoids environment-specific checks in the codebase, though it introduces a new configuration variable that users must set manually.

2. Allow a Termux-specific branch: Detect TERMUX_VERSION (Recommended)

• Narrow the target strictly to Termux by only using TMPDIR when TERMUX_VERSION is present, keeping /tmp as the default everywhere else.
• This is the most pragmatic and minimal fix—it requires no new imports or user configuration, works out-of-the-box on Termux across all Python versions, and has zero impact on standard Linux environments.
• However, since TERMUX_VERSION is a fairly common name combination, users who define it for other purposes—unaware that it triggers special behavior in python-xlib—could inadvertently expose themselves to the aforementioned TMPDIR security risks or connection issues. (To mitigate this risk, we could combine the check like if os.getenv('TERMUX_VERSION') and 'com.termux' in os.getenv('PREFIX', ''):.)

tmpdir = '/tmp'
if os.getenv('TERMUX_VERSION'):  # if os.getenv('TERMUX_VERSION') and 'com.termux' in os.getenv('PREFIX', ''):
    tmpdir = os.getenv('TMPDIR') or tmpdir
address = os.path.join(tmpdir, '.X11-unix', 'X%d' % dno)

Addressing this properly will likely require submitting a new PR. Before doing that, I would like to open this up for discussion and hear everyone's thoughts on which direction seems best.