got "Illegal instruction" in scipy.optimize.fmin_l_bfgs_b

[John-rhoades]

Binary package hint: python-scipy

Got an "Illegal instruction" fault when running the following test program using function fmin_l_bfgs_b from python package scipy.optimize. This worked fine on Ubuntu 10.10.

Test program:
--cut here--
import scipy.optimize

def f(x): return x[0]*x[0]+x[1]*x[1]
x0 = [1.0,1.0]
bnds = [ (-1.0, 1.0), (-1.0,1.0) ]
x,f,d = scipy.optimize.fmin_l_bfgs_b(f,x0,bounds=bnds,approx_grad=True)
print "x=",x," f=",f
--cut here--

Test results
jsr@artu:~/pc/python_experiments$ python test_optim.py
Illegal instruction

Expected results (run on Windows 7)
x= [ -5.01107818e-09 -5.01107818e-09] f= 5.02218089524e-17

Using Ubuntu 11.04 package python-scipy 0.8.0+dfsg1-1ubuntu1

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: python-scipy 0.8.0+dfsg1-1ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.42~ppa2-lowlatency 2.6.38.2
Uname: Linux 2.6.38-8-lowlatency i686
Architecture: i386
Date: Tue May 3 09:08:58 2011
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: python-scipy
UpgradeStatus: Upgraded to natty on 2011-04-30 (2 days ago)

[John-rhoades (john-rhoades)]

A clue: the test program works fine on a 64-bit version of Ubuntu 11.04.