Hi!

It would be great if the Ceres package supported optional features.

For example, metis is an optional part of Ceres, and not needed. It is quite a large package.

Second, openblas is also an optional dependency. In fact, it's quite huge. It downloads strawberry-perl, which apparently is a 32-bit portable version of Perl. It took ages to download and install and I don't even want to know how big it is. And now openblas has been building for the past half hour.

Third, suitesparse could also be made optional. It's not very large though and compiles "fairly" quickly so not a too huge issue, compared to the others.

It seems to me that the "Configuring" steps for glog is also taking quite a long time, not sure what's going on there, but the build is then rather quick.

In contrast to that, a lightweight, functional Ceres build only takes 5 or so minutes to compile with no additional downloads needed.