Tom Vincent

Essays on hacking, travel and self-improvement

Developers are users too!

Design for users is an oft cited, well grounded mantra in programming circles. However, us developers often forget about a principle user group: other developers. This post details a typical, frustrating afternoon for a developer dealing with new technologies.


Here’s the situation: I want to update Chromium’s userstyle CSS file with the latest Fanboy element hider rules. As hackers do, my first instinct is to write a script to do it for me. A few lines of Python later, and I’m faced with this:

Traceback (most recent call last):
urllib.error.URLError: <urlopen error [Errno 10060] A connection attempt failed
because the connected party did not properly respond after a period of time, or
established connection failed because connected host has failed to respond>

“Uh?! It must be that damn corporate firewall again.” Now, I’ve seen this one before and, armed with another script (to set up cmd with the correct proxy settings… yes, I’m running Windows here), I try again… with no joy:

File "C:\Python31\lib\http\", line 684, in _tunnel
for header, value in self._tunnel_headers.iteritems():
AttributeError: 'dict' object has no attribute 'iteritems'

“I’ll fix it later”, I think as I copy/paste the file manually.

YUI, You Eee?

“Hmm, I wonder if anyone’s thought of minifying userstyles?” With Fanboy’s CSS file, being ~4500 lines, it can’t be a bad idea. Having not used yuicompressor for a year or so now, I thought I’d take a look to see where the development has come since then.

The YUI Compressor homepage currently looks like this:

YUI Compressor homepage

OK, well, where’s the download link”. That’s a screenshot in a Chromium app window and still there’s another 2/3’rds to go. Scanning amongst the wall of text, I finally notice the unassuming download link:

The well-hidden YUI compressor download link

Latest (presumedly stable) build was 2009?!

YUI's last stable build was 2009

Oh, well, I’ve come this far, I might as well try it:

java -jar yuicompressor-2.4.2.jar Custom.css

Exception in thread "main" java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
Caused by: java.lang.IllegalArgumentException: Illegal group reference
        at java.util.regex.Matcher.appendReplacement(Unknown Source)
        ... 5 more

“Damnnn it!”.

Squashing bugs

The first result of a Google for yui InvocationTargetException returns a bug report, with a comment mentioning a fix(?) was committed in 2010. “OK, fine. It’s impossible to not notice the ‘Fork me on GitHub’ banner, so there must be a newer build there.”

“Damn, there are no pre-packaged builds. Nevermind, I’ll try building myself.” Noticing the build.xml file, I head over to download Apache Ant. While, I’ve never used ant before (I more versed with make), I know it’s a mature project, so things should go smoothly, right?

Ant, err, Ivy

A quick Google for apache ant gives me those handy links to directly jump to pages. “Hmm, what are those called again?”; google sitelinks. “Great! relevant-looking results”.

Google webmaster help pages

“This Help Centre is not currently available in your language.” “Argh!!” Just because I live in China, doesn’t mean I can speak Chinese. Where’s an English fall-back option? Oh, forget it.

The first result of a Google search for Apache Ant

Arrow as a clear metaphor for download

Nice, a nice easy download link.

java -jar ivy-2.2.0.jar
:: loading settings :: url = jar:file:/C:/Documents%20and%20Settings/user/My
:: resolving dependencies :: org.apache.ivy#ivy;2.2.0
        confs: [core, httpclient, oro, vfs, sftp, standalone, ant, default, test
, source]

Zzz. About a minute later and nothing happend. “Resolving dependencies… Oh, it’s trying to download something.” Firing up the aforementioned “cmd proxy setter” script, but no, still nothing.

Ant (round 2)

Something’s up here. I’ll rollback. Arbitrarily, I tried a DDG search instead.

Duck Duck Go's official site badge

Nice, an “official site” badge. I wonder how they determine that. Hmm, this is looking different…

Side-by-side view of the Apache Ant and Apache Ivy websites

Damn it! If this is ant, what did I just download? Pft, nevermind. Proceed to the download link.

Apache Ant's download sidebar

Good, nice and easy. Moving on…

Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre6\li
Buildfile: build.xml does not exist!
Build failed

Huh?! “Build failed”? I just wanted to see if it’ll run okay. And what’s this Java error? You didn’t mention anything about Java.

ant -h
Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre6\li
ant [options] [target [target2 [target3] ...]]
  -buildfile <file>      use given buildfile
    -file    <file>              ''
    -f       <file>              ''

Hmm, seems like an option to specify the build.xml location (though, isn’t that what [target] is?). Anyway, let’s try that:

ant -buildfile "C:\Documents and Settings\user\My Doc
Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre6\li
Buildfile: C:\Documents and Settings\user\My Documents\dwn\unsorted\yuicompr


    [javac] C:\Documents and Settings\user\My Documents\dwn\unsorted\yuicomp
ressor-2.4.2\yuicompressor-2.4.2\build.xml:23: warning: 'includeantruntime' was
not set, defaulting to build.sysclasspath=last; set to false for repeatable buil

C:\Documents and Settings\user\My Documents\dwn\unsorted\yuicompressor-2.4.2
\yuicompressor-2.4.2\build.xml:23: Unable to find a javac compiler; is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "C:\Program Files\Java\jre6"

Total time: 0 seconds

BUILD FAILED. Ah, now you tell me that I explicitly need JDK.

The Draconian Admin

OK (beleaguered by this point), let’s grab JDK.

Insufficient privileges error message from the Java installer

Despite my efforts (oh yes, yes, I tried), there’s no getting round this one.

Closing Points

Things don’t have be this hard! Design for users, yes, but don’t neglect fellow developers. Writing an API? Always prefer simple, well defined interfaces. Laboriously writing documentation for the sake of busywork? Stop. Rethink your design. It can always be simpler.

Developers are users too.