improve error handling

Cargo.lock

@@ -57,6 +57,7 @@ name = "libcsp-cargo-build"
 version = "0.2.0"
 dependencies = [
  "cc",
+ "thiserror",
 ]
 
 [[package]]
@@ -139,6 +140,26 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "thiserror"
+version = "1.0.61"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.61"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "toml_datetime"
 version = "0.6.6"

libcsp-cargo-build/Cargo.toml

@@ -12,3 +12,4 @@ categories = ["aerospace", "external-ffi-bindings", "no-std", "hardware-support"
 
 [dependencies]
 cc = "1"
+thiserror = "1"

libcsp-cargo-build/src/lib.rs

@@ -133,9 +133,11 @@ pub struct Builder {
     build: cc::Build,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 pub enum BuildCreationError {
+    #[error("The specified libcsp path does not exist")]
     PathDoesNotExist,
+    #[error("The specified libcsp path does not have the expected format of the library")]
     InvalidLibcspFormat,
 }