Can't launch wldash, if no mouse is connected.

[kkmp-dk]

I think it is a minor bug, but if you don't have a mouse connected you can't launch wldash in sway.

Not sure if it is a bug in your application or in wayland-client or sway.

To reproduce.

• Start sway (important don't have mouse connected)
• try launch wldash

Version

wldash version 0.2.0
sway version 1.6.1
wlroots 0.14.1-2

Stack trace

cargo run --release
thread 'main' panicked at 'unable to flush display: Os { code: 32, kind: BrokenPipe, message: "Broken pipe" }', src/app.rs:342:30
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Full backtrace

RUST_BACKTRACE=full cargo run --release
    Finished release [optimized] target(s) in 0.03s
     Running `target/release/wldash`
thread 'main' panicked at 'unable to flush display: Os { code: 32, kind: BrokenPipe, message: "Broken pipe" }', src/app.rs:342:30
stack backtrace:
   0:     0x55baa591db29 - std::backtrace_rs::backtrace::libunwind::trace::h7630ba4cba718aa0
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:     0x55baa591db29 - std::backtrace_rs::backtrace::trace_unsynchronized::he7498e79c157f5ac
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:     0x55baa591db29 - std::sys_common::backtrace::_print_fmt::hdaebadaee17bca49
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys_common/backtrace.rs:67:5
   3:     0x55baa591db29 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h82b0e3aaf8a96140
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys_common/backtrace.rs:46:22
   4:     0x55baa58cd9ec - core::fmt::write::h72801a82c94e6ff1
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/core/src/fmt/mod.rs:1149:17
   5:     0x55baa591c844 - std::io::Write::write_fmt::hc2da38dc44811df8
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/io/mod.rs:1697:15
   6:     0x55baa591cd7e - std::sys_common::backtrace::_print::h1c9a1d19c48821c1
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys_common/backtrace.rs:49:5
   7:     0x55baa591cd7e - std::sys_common::backtrace::print::h7ce8802039fa9d0e
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys_common/backtrace.rs:36:9
   8:     0x55baa591cd7e - std::panicking::default_hook::{{closure}}::hb2a74a8c1499c326
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:211:50
   9:     0x55baa591c5ef - std::panicking::default_hook::hf4f180b00076f2b2
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:228:9
  10:     0x55baa591c5ef - std::panicking::rust_panic_with_hook::he85ce8435493b711
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:606:17
  11:     0x55baa5942d13 - std::panicking::begin_panic_handler::{{closure}}::h31e15f69e6235bd2
  12:     0x55baa5942c96 - std::sys_common::backtrace::__rust_end_short_backtrace::hfce2fadb61aaa3ae
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/sys_common/backtrace.rs:139:18
  13:     0x55baa5942c52 - rust_begin_unwind
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/std/src/panicking.rs:498:5
  14:     0x55baa58c0330 - core::panicking::panic_fmt::h7b8580d81fcbbacd
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/core/src/panicking.rs:107:14
  15:     0x55baa58c0612 - core::result::unwrap_failed::h885d3f7beb571353
                               at /rustc/a77da2d454e6caa227a85b16410b95f93495e7e0/library/core/src/result.rs:1613:5
  16:     0x55baa5993142 - core::result::Result<T,E>::expect::h1df884c65bf7552e
  17:     0x55baa59acb95 - wldash::main::he9601f43d7218618
  18:     0x55baa59a4589 - std::sys_common::backtrace::__rust_begin_short_backtrace::h8bd52ec02aea305b
  19:     0x55baa59a9694 - main
  20:     0x7f5fbe5cfb25 - __libc_start_main
  21:     0x55baa58c52ce - _start
  22:                0x0 - <unknown>

The first stack trace I got is a little different I don't know why.
But I think this one is making more sense in a way of the mouse pointer was not plugged in.

[wayland-client] Protocol error while reading events: Protocol error 0 on object wl_seat@9: wl_seat.get_pointer called when no pointer capability has existed
Error while trying to read from the wayland socket: Os { code: 71, kind: Uncategorized, message: "Protocol error" }
thread 'main' panicked at 'unable to flush display: Os { code: 32, kind: BrokenPipe, message: "Broken pipe" }', src/app.rs:342:30
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[kennylevinsen]

Yeah, wldash is calling wl_seat::get_pointer during setup indiscriminately to handle mouse events. We should check if the pointer capability is present first. No need to check if it appears later - we'll handle it next time we run.