Implementing Solana IBC bridge, I had to deal with various constraints of the Solana protocol. Connecting Solana to Composable Foundation’s Picasso network, I needed to develop an on-chain light client capable of validating Tendermint blocks. This meant being able to validate 50 signatures in a single transaction.

Turns out that’s not possible on Solana and it’s not exactly because of the execution time limit. The real culprit is the transaction size limit which I’ve discussed previously. This article describes how signature verification is done on Solana, the limit on the number of signatures that can be verified in a single transaction and how that limit can be worked around.

Solana transactions are limited to 1232 bytes which was too restrictive when I was implementing Solana IBC bridge while working at Composable Foundation. The smart contract had to be able to ingest signed Tendermint block headers which were a few kilobytes in size.

To overcome this obstacle, I’ve used what I came to call chunking. By sending the instruction data in multiple transactions (similarly to the way Solana programs are deployed), the Solana IBC smart contract is capable of working on arbitrarily-large instructions. This article describes how this process works and how to incorporate it with other smart contracts (including those using the Anchor framework).

* available in Rust nightly.

There are several aspects of Rust that I’m not particularly fond of but the one that takes the cake is core::io::BorrowedBuf which I despise with passion. It’s a nightly feature which puts in question my extreme emotions about it. On the other hand it means there’s time to stop it from getting stabilised and figure out something better.

In this article I’ll describe the problem the feature addresses, the issues I have with the solution and describe some alternatives. As it turns out, things aren’t as easy as they seem on the first look.

In 2023 UniSuper, an Australian retirement fund, decided to migrate part of its operations to Google Cloud. As port of the migration, they needed to create virtual machines provisioned with limits higher than what Google’s user interface allowed to set. To achieve their goals, UniSuper contacted Google support. Having access to internal tools, Google engineer was able to create requested instances.

Fast forward to May 2024. UniSuper members lose access to their accounts. The fund blames Google. Some people are sceptical, but eventually UniSuper and Google Cloud publish a joint statement which points at ‘a misconfiguration during provisioning’ as cause of the outage. Later, a postmortem of the incident sheds even more light on events which have transpired.

Turns out that back in 2023, Google engineer used a command line tool to manually create cloud instances according to UniSuper’s requirements. Among various options, said tool had a switch setting cloud instance’s term. The engineer omitted it leading to the instance being created with a fixed term which triggered automatic deletion a year later.

So, human error. Scold the engineer and case closed. Or is it?

cd is a straightforward command. As per the name, it changes the directory and does its job perfectly well. But what if it could do more? One scenario is wanting to execute a command inside a specific location without affecting the current working directory (CWD). This article introduces a cd replacement which offers that feature as well as provides more ways to specify the target directory.

It is important to note that it’s not intended for scripting. Rather, it’s only meant for interactive use where it streamlines some operations.

Some people struggle to understand the distinctions between ‘free software’ and ‘open source software.’ Let’s clear up the confusion with an analogy.

Imagine a world without vegetarianism. One day, someone proposes a new diet called ‘moral eating,’ which excludes meat for ethical reasons. Some people embrace it, and discover additional benefits like reduced environmental impact. However, advocates observe that implying people not adhering to the diet are immoral isn’t the best recruitment strategy. They coin the term ‘sustainable eating’ to focus on the environmental advantages.

But now people get bogged down in philosophical debates. If one uses the term ‘moral eating’ some assume they don’t care about the environment; on the other hand, if one says ‘sustainable eating’ some assume they don’t care about animals. To avoid this an all-encompassing acronym MSE (Moral and Sustainable Eating) is created. It signifies the same thing — no meat — but avoids getting entangled in justifications.

And so we end up with three distinct terms — moral eating, sustainable eating and MSE — which all refer to the same diet. What we call vegetarianism.

TL;DR: When implementing Display trait for a wrapper type, use self.0.fmt(fmtr) rather than invoking write! macro. See The proper way section below.

No, I haven’t gone completely mad yet and still, I write this as an appeal to stop using monospaced fonts for code (conditions may apply). While fixed-width fonts have undeniable benefits when authoring software, their use is excessive and even detrimental in certain contexts. Specifically, when displaying inline code within a paragraph of text, proportional fonts are a better choice.

A quick reminder that relative URLs can start with a double slash and that this means something different than a single slash at the beginning. Specifically, such relative addresses are resolved by taking the schema (and only the schema) of the website they are on.

For example, the code for the link to my repositories in the site’s header is <a href="//codeberg.org/mina86">Code</a>. Since this page uses https schema, browsers will navigate to https://codeberg.org/mina86 if the link is activated.

This little trick can save you some typing, but more importantly, if you’re developing a URL parsing code or a crawler, make sure that it handles this case correctly. It may seem like a small detail, but it can have a lasting impact on the functionality of your code.

Or: How to change language of Google website.

If you’ve travelled abroad, you may have noticed that Google tries to be helpful and uses the language of the region you’re in on its websites. It doesn’t matter if your operating system is set to Spanish, for example; Google Search will still use Portuguese if you happen to be in Brazil.

Fortunately, there’s a simple way to force Google to use a specific language. All you need to do is append ?hl=lang to the website’s address, replacing lang with a two-letter code for the desired language. For instance, ?hl=es for Spanish, ?hl=ht for Haitian, or ?hl=uk for Ukrainian.

If the URL already contains a question mark, you need to append &hl=lang instead. Additionally, if it contains a hash symbol, you need to insert the string immediately before the hash symbol. For example:

• https://google.com/?hl=es
• https://google.com/search?q=bread+sandwich&hl=es
• https://analytics.google.com/analytics/web/?hl=es#/report-home/

By the way, as a legacy of Facebook having hired many ex-Google employees, the parameter also work on some of the Facebook properties.