Kev’s Blog – Page 208 – Kev's Development Toolbox

May 18, 2012

ruby gem error: “ERROR: While executing gem … (ConcurrencyError)”

On Windows 7 running ‘gem install [gem name]” I was getting this cryptic error:

ERROR: While executing gem … (ConcurrencyError)
Detected invalid array contents due to unsynchronized modifications with concurrent users

The only post I found that mentions this exact error was in the comments for this post about Neo4j on Ruby, and specifically getting this error with jruby 1.6.0.-RC2. I was using 1.6.0-RC1. I downloaded the latest version (1.6.7.2) and replaced my older version, and that fixed it.

May 17, 2012

Managing SSH keys on Heroku

Heroku uses Git for your code repo, and therefore uses SSH to talk to the remote server. If you’re already using an SSH keypair for another repo or elsewhere, you may have to explicitly manage which of your key’s you want to use to access Heroku.

To list your current keys you’ve shared with Heroku:

heroku keys

To add a new key – run this from your ~/.ssh/ dir:

heroku keys:add keyfilename (e.g. rsa_id.pub)

If you get this error:

Fingerprint already exists. Please use one SSH key per Heroku account

… it’s because you’ve already used this SSH key with another account.

May 9, 2012

Is Zuckerberg’s hoodie really ‘a mark of immaturity’?

An industry analyst who recently met with Zuckerberg about investment plans in Facebook stated that he thought Zuckerberg’s trademark hoodie is ‘a mark of immaturity’, implying that he should have been more suitably dressed for the business meeting.

Over on Google+, Robert Scoble posted about the analyst’s comment, which unleashed the most active community discussion that I’ve ever seen on G+ as a result of a single post. Opinions ranged wildly, but the activity in the discussion proves the absurdity and out of date thinking behind the expectation that professional business atire should be nothing other than suit, shirt and tie.

Times change, fashions change. The suit in today’s world is an absurd form of clothing. It has no practical benefits and is purely for show. This is my key issue – I don’t see how a suit is relevant in today’s world (in the software development world that I live in, at least) – wearing a suit does not make anyone a better software developer. It does not gift the developer with magical coding skills. It’s purely for show.

The popular saying ‘don’t judge a book by it’s cover’ hits the nail on the head with this issue. Wearing a suit is nothing more than a cover on a book. As the other expression goes, ‘first impressions count’, but the fact is, once you’ve got beyond that faux outer layer to discover the contents of the person that has wrapped themselves in fancy, overpriced fabrics, it’s hard to hide the facts without the flashy threads. In software development, you can either code or you can’t. You either gel with the team, or you don’t. You perform or you don’t. Each of these have varying levels of degree, but the key point is this: a suit is nothing more than fancy plumage. Remove the outer shell and show me what you’ve got.

There’s some awesome comments to Scoble’s post that capture my thoughts entirely, that I’d like to quote here that make the point perfectly:

"wearing a tie doesn't make you money, not unless you sell ties"

"If you need to wear a costume to play out your roles, you should 
have become an actor or actress long ago"

May 8, 2012

What did Jobs mean when he said he’d ‘cracked’ the TV format?

Apple has been rumored to be working on an Apple branded TV, and Jobs said about this new device that he’d ‘finally cracked it’, presumably meaning that he found a combination of features or new features that would make the killer Apple TV.

So what exactly did he have in mind? Most recent rumors from someone who claims to have seen an early prototype are that it’s a large flatscreen, with the Apple TV box integrated, a camera to support FaceTime, and Siri technology built in.

That doesn’t sound like a combination that would lead Jobs to say he’d ‘cracked’ it. Cracked what exactly? There must be more to it than just the combination of these components, because at face value that’s not exciting or revolutionary.

If I were to be interested in this product, it’s going to need to project a 3d hologram into the center of my living room. If Steve cracked that, then I’m buying.