May 27, 2009, 10:45 pm by
yiming
A new SelfSolved solution is up for perusal. The problem I tried to solve:
After compiling Subversion 1.6.2 from source on OS X 10.5 Leopard, the compilation is apparently successful, but svn dies when it tries to connect to the network for the first time. Crash log reports that symbols are missing from libneon.dylib.
Crash report from shell:
dyld: lazy symbol binding failed: Symbol not found: _ne_set_connect_timeout
Referenced from: /usr/local/lib/libsvn_ra_neon-1.0.dylib
Expected in: dynamic lookup
dyld: Symbol not found: _ne_set_connect_timeout
Referenced from: /usr/local/lib/libsvn_ra_neon-1.0.dylib
Expected in: dynamic lookup
Check out the places that I googled and my final solution writeup … at SelfSolved #49: Subversion 1.6.2 explodes on first network access.
The problem is very similar to a previous compilation issue I solved for PHP. In essence, the -L library search path passed to GCC at compilation time has /usr/lib in front of everything else. This means whatever library path you might have given to it at configure time, it’ll always look for the library in /usr/lib first, picking up the old system libneon in the process. Since the bad libneon dynamically linked, the problem doesn’t manifest itself until runtime — and only at runtime with network access involved.
As with the PHP issue, change the very first -L/usr/lib to -L/usr/local/lib (or wherever your newer libneon is located), and it’ll link correctly.
Out of curiosity, I checked MacPorts first. The MacPorts solution of disabling libneon version checking is odd — it also works, but I dunno if it’s linking to the right thing or not.
May 15, 2009, 2:16 pm by
yiming
A new SelfSolved problem is ready for perusal:
A couple of my iPhone projects require a decent HTML/XHTML parser. On OS X, Cocoa ships with NSXMLDocument, which includes dirty HTML parsing functionality from libtidy. Unfortunately, NSXMLDocument is not part of the actual iPhone 2.2 SDK (though it is part of the 2.2 Simulator — so it’ll compile just fine at dev time but break when deploying — a big gotcha if you never tested against a real iPhone).
NSXMLParser is a part of the iPhone SDK…This is not a reasonable alternative.
Check out my writeup at SelfSolved #42: HTML or XHTML Parser for iPhone SDK 2.x
Finally, all out of all the potential alternatives I found (all referenced at the SelfSolved writeup — including one that requires a license fee to use), this one seems to be the most promising and requires the least amount of pain (read: interaction with the libxml C API — god knows I’ve done enough of that while building prototypes at Yahoo! Research Berkeley)
May 1, 2009, 2:40 am by
yiming
MenuMeters is a very cool, free (as in freedom) system monitoring tool for OS X that sits in the menu bar and shows you live statistics, including such values as current bandwidth usage, current network activity, memory usage, page faults, etc.
One thing that has been irritating me lately is that there’s a cosmetic error MenuMeters 1.3 that causes negative values to appear in the VM Statistics section of the memory stats display. For example, the page faults value can roll over INT_MAX to report -1,800,000 page faults, when I’ve used the same OS X session for a long time without rebooting.
Since MenuMeters is GPL’ed, a quick lookthrough at its codebase reveals the problem. The details of this problem and solution is currently documented as #32 MenuMeters Memory Meter reports negative page faults at SelfSolved, a new web application I’ve written to keep track of these things.
More details to follow.
