[chshersh#150] Added more helpful error message if config toml file n…

…ot found (chshersh#150)

Resolves chshersh#150

- [ ] Documentation for changes provided/changed
- [ ] Tests added
- [ ] Updated CHANGELOG.md

src/config/toml.rs

@@ -80,7 +80,20 @@ pub fn with_parsed_file<F: FnOnce(Config)>(
 }
 
 fn parse_file(config_path: &PathBuf, proxy: Option<String>) -> Result<Config, TomlError> {
- let contents = fs::read_to_string(config_path).map_err(|e| TomlError::IO(format!("{}", e)))?;
+ let contents = fs::read_to_string(config_path).map_err(|e| match (&e, e.kind()) {
+ (e, std::io::ErrorKind::NotFound) => TomlError::IO(format!(
+"{}\n\nBefore using 'tool-sync', you need to configure it by specifying the location for downloading
+the tools and listing all the tools you want.
+
+'tool-sync' has a command to generate a default configuration with examples and field description. Simply generate it into a file and edit it:
+
+ tool default-config > ~/.tool.toml # generate the default config
+ vim ~/.tool.toml # open it with an editor of your choice
+
+By default 'tool-sync' reads the configuration from from the $HOME/.tool.toml path. But you can specify
+a custom location via the --config=/path/to/my/config flag.", e)),
+ (e, _) => TomlError::IO(format!("{}", e)),
+ })?;
 
  parse_string(&contents, proxy)
 }