How to do error handling in Rust and what are the common pitfalls?

Rust generally solves errors in two ways: Unrecoverable errors. Once you panic!, that’s it. Your program or thread aborts because it encounters something it can’t solve and its invariants have been violated. E.g. if you find invalid sequences in what should be a UTF-8 string. Recoverable errors. Also called failures in some documentation. Instead of … Read more

batch file test error level

IF ERRORLEVEL … is a special syntax supported since the DOS days, the %ERRORLEVEL% variable support was added in WinNT. The original syntax is used like this: call someapp.exe if errorlevel 1 goto handleerror1orhigher echo succuess… To use the variable, use the normal IF syntax: if %errorlevel%==0 echo success… Note that %errorlevel% stops working if … Read more

PHP Error handling: die() Vs trigger_error() Vs throw Exception

The first one should never be used in production code, since it’s transporting information irrelevant to end-users (a user can’t do anything about “Cannot connect to database”). You throw Exceptions if you know that at a certain critical code point, your application can fail and you want your code to recover across multiple call-levels. trigger_error() … Read more

Custom error pages for 404, 500 but where is the default 500 error message coming from?

Our exception_handler gem can be used for Ruby on Rails custom error pages. How It Works All Ruby on Rails exceptions are handled with config.exceptions_app. This is assigned in the config/application.rb or config/environments/*.rb files – it needs to be a callback: config.exceptions_app sets the exceptions application invoked by the ShowException middleware when an exception happens. … Read more

Analytics Google API Error 403: “User does not have any Google Analytics Account”

I had this problem too. I fixed it by adding the email address for my service account to the Google Analytics profile I wanted it to access. I got the email address (something like [email protected]) for the service account by looking under the “API Access” tab in the Google APIs console. Then, I followed Google’s … Read more

Unable to read file contents to string – Result does not implement any method in scope named `read_to_string`

Let’s look at your error message: error[E0599]: no method named `read_to_string` found for type `std::result::Result<std::fs::File, std::io::Error>` in the current scope –> src/ | 11 | file.read_to_string(&mut s); | ^^^^^^^^^^^^^^ method not found in `std::result::Result<std::fs::File, std::io::Error>` The error message is pretty much what it says on the tin – the type Result does not have the … Read more