Loader error in my rb1d/upcxx app

[Scott Baden]

The app "rb1d-lbarr" fails to build [it's in the scott repo under rb1d/upcxx, and you have read permissions]

I'd been having trouble with the app hanging, so I deleted my upcxx installation including .nobs and rebuilt from scratch. The build of the app is attached, showing the loader errors

This is on my office mac

[Dan Bonachea]

@sbbaden : are you able to build the programming guide examples in upcxx/example/prog-guide using your install?

gmake -C example/prog-guide UPCXX_INSTALL=/path/to/upcxx/install clean all

The answer will help us narrow down the problem.

[Paul Hargrove]

@sbaden I see the following in the link command of your output:
-L/usr/local/lib/gcc/x86_64-apple-darwin15.6.0/6.2.0
So, I assume that UPC++ was built with CXX pointing to (or defaulting to) an install of g++-6.2.0.
However, based on the message clang: warning: argument unused... you appear to be compiling and linking your application with clang.

I suspect the problem is that clang++ and g++ may be using different C++ standard libraries.
So, I recommend you ensure that you are using the same compiler for both UPC++ and your application.
For instance, if your Makefile does not already use upcxx-meta to determine the C++ compiler, then that would be the first thing to change.

[Scott Baden]

The outcome of compiling the prog-guide examples

[Dan Bonachea]

Given hello-world is failing to build for you (but works in nightly tests that include mac) this looks like a broken install.

Please try:

cd upcxxsrcdir ; rm -Rf .nobs $UPCXX_INSTALL ; ./install $UPCXX_INSTALL

and capture the full output of the install command.

[Scott Baden]

I had to rejuvenate 2 lines in my .tcshrc file that set CXX and CC to /usr/bin/g++ and /usr/bin/gcc

$CXX -v Apple LLVM version 9.0.0 (clang-900.0.38) Target: x86_64-apple-darwin16.7.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

I now got further with the build of the PG examples, but clang comlained about -fopenmp in the build of persona-example

clang: error: unsupported option '-fopenmp'

Note also that rb1d-lbarr fails now. It hangs. This code worked, then didn't work, then work, now didn't work again. Hadia and I observed it fail yesterday in my office, after I'd tested it on another mac over the weekend. When I wiped the rb1d repo and re-cloned, it worked. But now it hangs today. Same behavior on Edison and Hadia has observed the failure independently.

[Scott Baden]

Dan, I've attached the output of the installation.

[Dan Bonachea]

clang comlained about -fopenmp in the build of persona-example

Apple clang lacks OpenMP support, so this test won't work when using /usr/bin/{gcc,g++}.

Also note we have some known open issues with homebrew gcc on mac - issue #49, issue #92, so I would stay away from that and stick to /usr/bin/{gcc,g++} until those are resolved.

So it sounds like the compilation/linking problem is solved.

If rb1d is compiling but failing at runtime, that should probably be opened as a separate issue (and probably assigned to Hadia to narrow down). In particular, you'll need to report which of the many versions you are running and with which parameters.

[Scott Baden]

We need to be clear in the INSTALL.md that Mac users should not use the Brew install as this is a known issue But it also sounds like something changed in the build, that wasn't causing a problem before....

It is odd that the program ran correctly and reliably many times over . Will start an issue in my repo