Support multiple exit codes

..with more specific error enums.

cli/src/invocation/cmd/add.rs

@@ -6,7 +6,7 @@ pub(crate) fn execute<W: WriteColor>(
     w: &mut W,
     replica: &mut Replica,
     modification: Modification,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     let description = match modification.description {
         DescriptionMod::Set(ref s) => s.clone(),
         _ => "(no description)".to_owned(),

cli/src/invocation/cmd/config.rs

@@ -6,7 +6,7 @@ pub(crate) fn execute<W: WriteColor>(
     w: &mut W,
     config_operation: ConfigOperation,
     settings: &Settings,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     match config_operation {
         ConfigOperation::Set(key, value) => {
             let filename = settings.set(&key, &value)?;

cli/src/invocation/cmd/gc.rs

@@ -1,7 +1,7 @@
 use taskchampion::Replica;
 use termcolor::WriteColor;
 
-pub(crate) fn execute<W: WriteColor>(w: &mut W, replica: &mut Replica) -> anyhow::Result<()> {
+pub(crate) fn execute<W: WriteColor>(w: &mut W, replica: &mut Replica) -> Result<(), crate::Error> {
     log::debug!("rebuilding working set");
     replica.rebuild_working_set(true)?;
     writeln!(w, "garbage collected.")?;

cli/src/invocation/cmd/help.rs

@@ -5,7 +5,7 @@ pub(crate) fn execute<W: WriteColor>(
     w: &mut W,
     command_name: String,
     summary: bool,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     let usage = Usage::new();
     usage.write_help(w, command_name.as_ref(), summary)?;
     Ok(())

cli/src/invocation/cmd/info.rs

@@ -10,7 +10,7 @@ pub(crate) fn execute<W: WriteColor>(
     replica: &mut Replica,
     filter: Filter,
     debug: bool,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     let working_set = replica.working_set()?;
 
     for task in filtered_tasks(replica, &filter)? {

cli/src/invocation/cmd/modify.rs

@@ -8,7 +8,7 @@ pub(crate) fn execute<W: WriteColor>(
     replica: &mut Replica,
     filter: Filter,
     modification: Modification,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     for task in filtered_tasks(replica, &filter)? {
         let mut task = task.into_mut(replica);
 

cli/src/invocation/cmd/report.rs

@@ -10,7 +10,7 @@ pub(crate) fn execute<W: WriteColor>(
     settings: &Settings,
     report_name: String,
     filter: Filter,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     display_report(w, replica, settings, report_name, filter)
 }
 

cli/src/invocation/cmd/sync.rs

@@ -5,7 +5,7 @@ pub(crate) fn execute<W: WriteColor>(
     w: &mut W,
     replica: &mut Replica,
     server: &mut Box<dyn Server>,
-) -> anyhow::Result<()> {
+) -> Result<(), crate::Error> {
     replica.sync(server)?;
     writeln!(w, "sync complete.")?;
     Ok(())

cli/src/invocation/cmd/version.rs

@@ -1,6 +1,6 @@
 use termcolor::{ColorSpec, WriteColor};
 
-pub(crate) fn execute<W: WriteColor>(w: &mut W) -> anyhow::Result<()> {
+pub(crate) fn execute<W: WriteColor>(w: &mut W) -> Result<(), crate::Error> {
     write!(w, "TaskChampion ")?;
     w.set_color(ColorSpec::new().set_bold(true))?;
     writeln!(w, "{}", env!("CARGO_PKG_VERSION"))?;