Error Using Eigen 'sqrt' While Compiling ROS PCL

Question

I'm trying to re-install ROS in order to get a clean configuration to solve some other issues, and the build is failing when it gets to the 'pcl' package. It seems to just repeat this error:

In file included from /home/abouchard/ros_catkin_ws/src/pcl/common/include/pcl/common/vector_average.h:40:0,
                 from /home/abouchard/ros_catkin_ws/src/pcl/common/test/test_vector_average.cpp:42:
/home/abouchard/ros_catkin_ws/src/pcl/common/include/pcl/common/eigen.h: In function ‘void pcl::computeRoots(const Matrix&, Roots&)’:
/home/abouchard/ros_catkin_ws/src/pcl/common/include/pcl/common/eigen.h:168:30: error: ‘sqrt’ is not a member of ‘Eigen::internal’

The specific line numbers and such vary, of course, but they all have to do with a call to a sqrt function, and the namespace is either Eigen or pcl. I've Googled the error to little avail, and I am loathe to change the code much since I'm assuming there was some reason to call out a sqrt function other than the one in the 'math' library.

I found the documentation for the 'internal' namespace in Eigen, and it doesn't appear to have a sqrt function. However, looking at the file causing the issue (eigen.h), it seems to make some custom declarations of the sqrt function, but just for the pcl namespace.

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Originally posted by teddybouch on ROS Answers with karma: 320 on 2013-09-03

Post score: 2

Answer 1

In eigen.h: -replace all instances of Eigen::internal::sqrt with pcl::sqrt -replace all instances of Eigen::sin/cos with sin/cos

This allows it to compile successfully, but I haven't tested thoroughly to see whether it affects functionality. A co-worker of mine ran into the same problem and used std::sqrt instead of pcl::sqrt, and his compiles as well.

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Originally posted by teddybouch with karma: 320 on 2013-09-04

This answer was ACCEPTED on the original site

Post score: 3

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Original comments

Comment by teddybouch on 2013-09-20:
Until I find that either solution creates a problem, I am going to flag this as a solution.

Comment by mz on 2015-06-15:
Looks like Eigen did remove Eigen::internal::sqrt() and was okay with using std::sqrt() http://eigen.tuxfamily.org/bz/show_bug.cgi?id=264 and Eigen::internal::sin and cos as well http://listengine.tuxfamily.org/lists.tuxfamily.org/eigen/2012/11/msg00002.html