evaluate-sequence fails on 6.7.7-2_0 Q16

[alosca]

I am getting the following Abort when trying -evaluate-sequence on four tiff images ($l below is a shell variable) after an upgrade yesterday to 6.7.7-2_0+q16 on OS X using Macports. I switched back to 6.7.6-0_0+q16 and things are back to normal. The image files are fine. A bug? Running on x86_64 Darwin Kernel Version 10.8.0.

- alosca

bamboo [195] : convert --version
Version: ImageMagick 6.7.7-2 2012-05-30 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP OpenCL

bamboo [166] : convert $l[1-4] -evaluate-sequence max tiff:- | display
Assertion failed: (id < (int) cache_view->number_threads), function GetCacheViewVirtualPixels, file magick/cache-view.c, line 729.
Assertion failed: (id < (int) cache_view->number_threads), function GetCacheViewVirtualPixels, file magick/cache-view.c, line 729.
Assertion failed: (id < (int) cache_view->number_threads), function GetCacheViewVirtualPixels, file magick/cache-view.c, line 729.
Abort

bamboo [202] : echo $l[1-4]
test.001.tiff test.002.tiff test.003.tiff test.004.tiff

bamboo [203] : tiffinfo test.003.tiff
TIFF Directory at offset 0x40008 (262152)
Image Width: 512 Image Length: 512
Resolution: 72, 72 (unitless)
Bits/Sample: 8
Compression Scheme: None
Photometric Interpretation: min-is-black
FillOrder: msb-to-lsb
Orientation: row 0 top, col 0 lhs
Samples/Pixel: 1
Rows/Strip: 16
Planar Configuration: single image plane
Page Number: 0-1
DocumentName: /var/folders/fm/fm3FU+QoGpSqFFmaTr1jrU+++TI/-Tmp-/magick-4ikrd8qy
White Point: 0.3127-0.329
PrimaryChromaticities: 0.640000,0.330000,0.300000,0.600000,0.150000,0.060000

[magick]

Perhaps a transient bug. We tried your commands with ImageMagick-6.7.7-6 release and could not reproduce the assertion. If you do reinstall 6.7.2-2, try adding -limit thread 4 to your command line. If that fails, try -limit thread 1.

[alosca]

I re-activated 6.7.7-2 and the error is gone only when limiting to a single thread, -limit thread 1. Any way this can be fixed to take advantage of all available cores? I assume -limit thus actually limits the number of threads/cores.

I am using Macports to get the latest IM so I am not sure I can control the compilation. Any recommendations of how to do that are appreciated. Or maybe a Macport repository with the latest stable for OS X 10.8.0?

bamboo [367] : convert --version
Version: ImageMagick 6.7.7-2 2012-05-30 Q16 http://www.imagemagick.org
Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC
Features: OpenMP OpenCL