diff --git a/Cargo.lock b/Cargo.lock
index 8ae5371..6085d36 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -59,6 +59,12 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86fdf8605db99b54d3cd748a44c6d04df638eb5dafb219b135d0149bd0db01f6"
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -137,6 +143,7 @@ checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
 name = "conventional_commits_next_version"
 version = "6.0.1"
 dependencies = [
+ "anyhow",
  "clap",
  "git2",
  "lazy_static",
diff --git a/Cargo.toml b/Cargo.toml
index 50daa54..55b6ce8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -33,6 +33,9 @@ lazy_static = "1.4.0"
 strum = "0.26.0"
 strum_macros = "0.26.0"
 
+# For error handling.
+anyhow = "1.0.89"
+
 
 [dev-dependencies]
 # For parameterized testing.
diff --git a/end-to-end-tests/features/steps/assertions.py b/end-to-end-tests/features/steps/assertions.py
index ff66106..7bd5616 100644
--- a/end-to-end-tests/features/steps/assertions.py
+++ b/end-to-end-tests/features/steps/assertions.py
@@ -24,6 +24,12 @@ def assert_error_equals(result, error):
         f"Error          = {error.encode()}.\n"
 
 
+def assert_error_contains(result, error):
+    assert error in result.stderr, "Expected standard error to contain the error.\n" + \
+        f"Standard error = {result.stderr.encode()}.\n" + \
+        f"Error          = {error.encode()}.\n"
+
+
 def assert_error_matches_regex(result, regex):
     assert regex.match(result.stderr) is not None, f"Expected standard errors to match the regex.\n" + \
         f"Standard error = {result.stderr.encode()}.\n" + \
diff --git a/src/main.rs b/src/main.rs
index eb4fefc..de3a0e2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,13 +6,12 @@ extern crate pretty_env_logger;
 
 use std::io::{stdin, Read};
 
+use anyhow::{bail, Result};
 use clap::Parser;
 use git2::Repository;
 
-pub use crate::calculation_mode::CalculationMode;
 use crate::cli::Arguments;
-pub use crate::commits::Commits;
-pub use crate::git_history_mode::GitHistoryMode;
+use crate::commits::Commits;
 
 mod calculation_mode;
 mod cli;
@@ -27,12 +26,13 @@ fn main() {
     let arguments = Arguments::parse();
     trace!("The command line arguments provided are {arguments:?}.");
 
-    if run(arguments).is_err() {
+    if let Err(err) = run(arguments) {
+        error!("{:?}", err);
         std::process::exit(ERROR_EXIT_CODE);
     }
 }
 
-fn run(arguments: Arguments) -> Result<(), git2::Error> {
+fn run(arguments: Arguments) -> Result<()> {
     let commits = match (
         arguments.from_stdin,
         arguments.from_commit_hash,
@@ -63,7 +63,7 @@ fn run(arguments: Arguments) -> Result<(), git2::Error> {
             )
         }
         (_, _, _) => {
-            unreachable!("Invalid combination of arguments.");
+            bail!("Invalid combination of arguments.");
         }
     }?;
     let expected_version =
@@ -71,9 +71,7 @@ fn run(arguments: Arguments) -> Result<(), git2::Error> {
 
     if let Some(current_version) = arguments.current_version {
         if current_version < expected_version {
-            let error_message = format!("The current version {current_version} is not larger or equal to the expected version {expected_version}.");
-            error!("{error_message}");
-            return Err(git2::Error::from_str(&error_message));
+            bail!(format!("The current version {current_version} is not larger or equal to the expected version {expected_version}."));
         }
         info!("The current version {current_version} is larger or equal to the expected version {expected_version}.");
     } else {