[yabridgectl] Check for libdbus-1.so

Instead of checking for notify-send.

tools/yabridgectl/Cargo.lock

@@ -311,6 +311,16 @@ version = "0.2.126"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "349d5a591cd28b49e1d1037471617a32ddcda5731b99419008085f72d5a53836"
 
+[[package]]
+name = "libloading"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "efbc0f03f9a775e9f6aed295c6a1ba2253c5757a9e03d55c6caa46a681abcddd"
+dependencies = [
+ "cfg-if",
+ "winapi",
+]
+
 [[package]]
 name = "linux-raw-sys"
 version = "0.0.46"
@@ -832,6 +842,7 @@ dependencies = [
  "colored",
  "goblin",
  "is_executable",
+ "libloading",
  "promptly",
  "rayon",
  "reflink",

tools/yabridgectl/Cargo.toml

@@ -15,6 +15,7 @@ clap = { version = "3.0.6", features = ["cargo", "env", "wrap_help"] }
 colored = "2.0.0"
 is_executable = "1.0.1"
 goblin = { version = "0.6", default_features = false, features = ["std", "pe32", "pe64"] }
+libloading = "0.7.3"
 promptly = "0.3.1"
 # Version 0.1.3 from crates.io assumes a 64-bit toolchain
 reflink = { git = "https://github.com/nicokoch/reflink", rev = "e8d93b465f5d9ad340cd052b64bbc77b8ee107e2" }

tools/yabridgectl/src/actions.rs

@@ -833,8 +833,9 @@ pub fn do_sync(config: &mut Config, options: &SyncOptions) -> Result<()> {
     // This check is only performed once per combination of Wine and yabridge versions
     verify_wine_setup(config)?;
 
-    // Yabridge uses notify-send to relay important information when something's very wrong, so
+    // Yabridge uses D-Bus notifications to relay important information when something's very wrong,
-    // we'll check whether this is installed
+    // so we'll check whether `libdbus-1.so` is available (even though it would be very odd if it
+    // isn't)
     verify_external_dependencies()?;
 
     Ok(())

tools/yabridgectl/src/util.rs

@@ -29,7 +29,6 @@ use std::os::unix::process::CommandExt;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 use textwrap::Wrapper;
-use which::which;
 
 use crate::config::{self, Config, KnownConfig, YABRIDGE_HOST_32_EXE_NAME, YABRIDGE_HOST_EXE_NAME};
 use crate::files::{LibArchitecture, NativeFile};
@@ -465,18 +464,20 @@ pub fn verify_wine_setup(config: &mut Config) -> Result<()> {
     Ok(())
 }
 
-/// Check whether `notify-send` is installed, as this is used to relay important information when
+/// Check whether yabridge's (optional) external dependencies are installed. Right now this only
-/// something's very wrong.
+/// checks for libdbus, as this is used to relay important information when something's very wrong.
 pub fn verify_external_dependencies() -> Result<()> {
-    if which("notify-send").is_err() {
+    let libdbus_name = libloading::library_filename("dbus-1");
+    let libdbus_available = unsafe { libloading::Library::new(&libdbus_name) }.is_ok();
+    if !libdbus_available {
         eprintln!(
             "\n{}",
             wrap(&format!(
                 "Warning: Could not find '{}'. This will not prevent yabridge from working, but \
-                 you will also not receive any notifcations when something is wrong. It is \
+                 you will also not receive any notifcations when something is wrong. D-Bus should \
-                 usually part of the libnotify package, but your distro might have moved it into \
+                 already be installed on the system, so if you're seeing this warning then \
-                 a separate libnotify-tools package.",
+                 something is probably very wrong.",
-                "notify-send".bright_white(),
+                libdbus_name.to_str().unwrap().bright_white(),
             ))
         );
     }