refactor error handling

Cargo.toml

@@ -3,17 +3,29 @@ name = "bmputil"
 version = "0.1.0"
 edition = "2021"
 
+[features]
+# Enable backtraces for errors. Requires nightly toolchain.
+# Automatically enabled if detect-backtrace feature is enabled (default).
+backtrace = []
+# Autoamtically detect if backtrace feature should be enabled by detecting the channel we're being compiled on.
+detect-backtrace = []
+default = ["detect-backtrace"]
+
 [dependencies]
 clap = { version = "3.0", default-features = false, features = ["std", "color"] }
 env_logger = "0.9"
 dfu-core = { version = "0.2", features = ["std"] }
 dfu-libusb = "0.2"
 rusb = "0.9"
 log = "0.4"
+const_format = "0.2"
 anyhow = "1.0"
 thiserror = "1.0"
 indicatif = "0.16"
 
+[build-dependencies]
+rustc_version = "0.4"
+
 [profile.release]
 lto = "fat"
 

build.rs

@@ -0,0 +1,23 @@
+
+use rustc_version::{version_meta, Channel};
+
+fn main()
+{
+    // If detect-backtrace is enabled (default), detect if we're on nightly or not.
+    // If we're on nightly, enable backtraces automatically.
+    match std::env::var_os("CARGO_FEATURE_DETECT_BACKTRACE") {
+        Some(_val) => {
+            match version_meta() {
+                Ok(version_meta) => {
+                    if version_meta.channel == Channel::Nightly {
+                        println!("cargo:rustc-cfg=feature=\"backtrace\"");
+                    }
+                },
+                Err(e) => {
+                    println!("cargo:warning=error detecting rustc version: {}", e);
+                }
+            }
+        },
+        None => (),
+    }
+}