Ethereum: Bitcore = «Error: More than one instance of bitcore-lib found»

Ethereum 2.0 and Bitcoined: A Cautionary Tale of Over-Dependency

In the rapidly evolving world of Ethereum 2.0, a simple yet crucial step has gone unnoticed by many developers. The lines var exp = require('bitcore-explorers'); and var btc=require('bitcore-lib'); create an error known as «More than one instance of bitcore-lib found. This warning serves as a timely reminder to exercise caution when importing libraries into your code.

The Issue

At first glance, these lines appear innocuous. They import two instances of the bitcore library: exp and btc. However, this creates an issue with the way JavaScript handles imports. When multiple libraries are imported within the same scope (i.e., module), it can lead to conflicts and errors.

The Cause

In Node.js, when you require a library, it checks if that library is already being used in your current scope. If it finds another instance of the same library, it throws an error. This is known as «more than one instance» or «duplicate imports.

To illustrate this, imagine two developers working on the same project:

• Developer A uses bitcore-explorers and bitcore-lib in their code.

• Developer B uses bitcore-explorers and another-bitcore-lib.

In this scenario, both developers are using the same instance of bitcore, which would cause a conflict. This is precisely what’s happening when we encounter the «More than one instance» error.

The Solution

To resolve this issue, developers should follow best practices for importing libraries into their code:

• Use the exact library name (e.g., bitcore-explorers instead of bitcore-lib). This ensures that each import is unique and not a duplicate.

• Avoid importing multiple instances of the same library within the same scope. Instead, consider reorganizing your code to reduce dependencies.

A Solution

To fix this issue in our original example:

var exp = require('

var btc = require('bitcore-lib');

By using the exact library name and Avoiding duplicate imports, we can resolve the «More than one instance of bitcore-lib found» error.

Conclusion

As developers continue to build and maintain Ethereum 2.0 projects, it’s essential to be mindful of library dependencies and import them correctly. By following best practices for importing libraries, you can avoid conflicts and ensure your code remains stable and reliable. Remember: a simple oversight can lead to a more complex debugging process – so take the time to ensure your imports are accurate!