How Do You Troubleshoot the Cargo/Rust Error “use of undeclared type or module”?

Problem Scenario
You run a “cargo run” command. You get an error like one or more of the following:

use of undeclared type or module api

use of undeclared type or module serde_json

use of undeclared type or module async-std

What should you do?

Solution
Update the Cargo.toml file. The dependencies section should have an entry like one of the following (but the version number may or may not differ):

[package]
name = “in3-tutorial”
version = “0.0.1”
authors = [”reader@medium.com”]
edition = “2018”

[dependencies]
in3 = “0.1.7”
async-std = “1.5.0”
futures-executor = “0.3.5”
serde_json = “1.0”
ethabi = “13.0.0”
ethereum_abi = “0.2.0”
ethbloom = “0.10.0”

[[bin]]
name = “in3”
path = “/home/jdoe/rust/contint.rs”

If you are not sure what version is valid,

How Do You Troubleshoot “cp: cannot stat …: No such file or directory” when Running build_rust.sh?

Problem scenario
You are running build_rust.sh to use Blockchains’ Incubed. But you get an error message like this:

cp: cannot stat ‘c/CMakeLists.txt’: No such file or directory
cp: cannot stat ‘c/macro.cmake’: No such file or directory
cp: cannot stat ‘c/compiler.cmake’: No such file or directory
cp: cannot stat ‘c/docs’: No such file or directory
cp: cannot stat ‘c/src’: No such file or directory
cp: cannot stat ‘c/include’: No such file or directory
cp: cannot stat ‘CMakeLists.txt’: No such file or directory

What should you do?

How Do You Get Python to Search a Web Page for a Specific Pattern?

Problem scenario
How do you write a Python 3 program to parse the text of a web page and determine if a string is on the web page or not?

Solution
Change the “yoururl” variable assignment and the “searchterm” assignment below to what you desire. Then run the program below:

import re
import requests
yoururl = ‘https://www.continualintegration.com/’
searchterm = “learned”
r = requests.get(yoururl)
found = re.search(searchterm, …

How Do You Write a Python Program to Test if Integers Are in Order?

Problem scenario
You need to write a Python program to see if a list of unique integers is in order. You can copy the list and sort it to compare the ideal state to the list provided. The program must print out a relevant message if a swap of two numbers can place those two numbers in the correct order. The program must print out if a given number is already in order.

How Do You Configure Nginx to Listen to Messages Sent via HTTP?

Problem scenario
You have Nginx configured. The access logs never pick up any POST message content. You get 405 error messages. What do you do?

Solution
This will send a message payload — but not via POST. It may not work for your situation. To get a message to be sent to a website (a listening web service), craft a URL that does not necessarily exist,