This formula cannot be built with any available compilers

[lifepillar]

I've got the error “This formula cannot be built with any available compilers” for a couple of formulas since I have upgraded to OS X Mavericks. So, I have decided to re-install Homebrew from scratch. Now, I'm getting that error when trying to install mariadb:

brew  install -vD mariadb
Error: This formula cannot be built with any available compilers.
To install this formula, you may need to:
  brew install apple-gcc42

Installing apple-gcc42 does not fix it (I think the error message is misleading).

My brew --config:

HOMEBREW_VERSION: 0.9.5
ORIGIN: https://github.com/mxcl/homebrew
HEAD: dde0fbd8349594b036666eea02a075b6668003dc
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CELLAR: /usr/local/Cellar
CPU: quad-core 64-bit sandybridge
OS X: 10.9-x86_64
Xcode: 5.0.1
CLT: 5.0.1.0.1.1382131676
Clang: 5.0 build 500
X11: 2.7.4 => /opt/X11
System Ruby: 1.8.7-358
Perl: /usr/bin/perl
Python: /usr/bin/python
Ruby: /usr/bin/ruby => /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/bin/ruby

I have installed the Xcode command-line tools, too. Am I missing some other step?

[MikeMcQuaid]

The error message is correct. This will be another issue. However, as you've posted no debugging information we're unable to help further. Please read this: https://github.com/mxcl/homebrew/wiki/Troubleshooting

[lifepillar]

I've posted all the debugging information I get from brew install -v mariadb 2>&1 (before and after installing apple-gcc42 there's no difference). No log file is written, either.

One thing I've noticed, there's no LLVM-GCC line in the output of brew --config. Is that expected on Mavericks? I have llvm-gcc in /usr/bin. Apparently, MariaDB does not build with Clang, so that may be the reason.

Other formulas (for example, postgresql) build fine, and my system is raring to brew.

[MikeMcQuaid]

Can you paste the output of brew uninstall apple-gcc42; brew install -v apple-gcc42 mariadb, please.

[lifepillar]

Here it is: http://gist.github.com/lifepillar/7153442. Anyway, I've got MariaDB to build with --use-llvm.

I remember that, in these cases, Homebrew used to spit a warning along the lines: “this formula is reported not to build with clang; please, try --use-llvm or --use-gcc”. This is what I expected to see in this case, too.

[MikeMcQuaid]

Very strange. @mistydemeo This seems like it may be an edge case?

[lifepillar]

I've just learned that Apple has dropped LLVM-GCC from Xcode 5 (https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/WhatsNewXcode/Articles/xcode_5_0.html).

I was able to build MariaDB “by chance”, because in the past I had manually installed llvm-gcc-4.2 in /usr and had created the following symlinks in /usr/bin:

/usr/bin/llvm-cpp-4.2 -> ../llvm-gcc-4.2/bin/llvm-cpp-4.2
/usr/bin/llvm-g++-4.2 -> ../llvm-gcc-4.2/bin/llvm-g++-4.2
/usr/bin/llvm-gcc-4.2 -> ../llvm-gcc-4.2/bin/llvm-gcc-4.2

(Interestingly enough, upgrading from 10.8 to 10.9 did not remove those symlinks and the llvm-gcc-4.2 directory.)

I have now deleted those symlinks and tried to build MariaDB again with --use-llvm, and, as expected, it fails.

Maybe, llvm-gcc could be added to Homebrew to let all formulas that don't build on Clang to continue to work? Would that be possible without creating a mess? Think about formulas B and C, both depending on formula A; formula B builds with Clang, but formula C requires --use-llvm. Now, assume that you brew B first, compiling B and A with Clang and libc++; then, formula C won't build with or without --use-llvm; in the former case, because Homebrew would complain about A being built with libc++ (Clang) instead of libstdc++ (llvm). I have already stumbled upon this situation and I don't know what to do.

[mistydemeo]

Interesting that Homebrew didn't pick up on those links for fails_with fallbacks, but allows it for --use-llvm.

Maybe, llvm-gcc could be added to Homebrew to let all formulas that don't build on Clang to continue to work?

We already include an apple-gcc42 formula for the same use case! llvm-gcc is a modified version of gcc-4.2, so from your perspective there's not really a reason to prefer llvm-gcc.

I have already stumbled upon this situation and I don't know what to do.

This is definitely a mess, but unfortunately there's not much we can do about it until authors fix their software with clang. :/ Since Apple only ships clang now, it's the compiler we'll be preferring going forward.

[lifepillar]

We already include an apple-gcc42 formula for the same use case! llvm-gcc is a modified version of gcc-4.2, so from your perspective there's not really a reason to prefer llvm-gcc.

That's fine. Shouldn't be better to drop, or at least deprecate, --use-llvm then?

Unfortunately there's not much we can do about it until authors fix their software with clang.

I'm pretty sure that in the past I had built a few formulas with gcc, but I've never had those conflicts between libc++ and libstdc++ that I'm seeing now that I'm re-installing on 10.9. Have I been just lucky or something has changed in 10.9 that causes those errors?

[mistydemeo]

That's fine. Shouldn't be better to drop, or at least deprecate, --use-llvm then?

We've kept it around for the sake of users on older OS X versions whose Xcodes don't include gcc-4.2, but do include llvm-gcc.

Have I been just lucky or something has changed in 10.9 that causes those errors?

10.9 changed the default C++ standard library. On 10.8 and below, clang's default was libstdc++, so it was compatible with Apple-provided GCCs. On 10.9 it's now libc++.

[gregbair]

I also just ran into this. After installing apple-gcc42, I was able to successfully install mariadb -

==> Summary
🍺 /usr/local/Cellar/mariadb/5.5.32: 481 files, 114M, built in 6.8 minutes

[lifepillar]

Ok, so brew install apple-gcc42; brew install mariadb --use-gcc solves this issue.

[gregbair]

Actually, it's just brew install apple-gcc42; brew install mariadb. Didn't have to use --use-gcc.

[lifepillar]

Correct. It was failing for me earlier because I had messed up with my system.