Fixing env variables/arguments in OpenBSD build instructions #11921

When the before version of the commands are executed, ./configure fails with:

 configure: error: C compiler cannot create executables

However, when the arguments are passed as environment variables rather than arguments (at least on BSD), the ./configure runs with no issues and the build succeeds.

Will try to reproduce this - the last time I tried the OpenBSD build instructions they worked fine for me.

The reason we pass those options as arguments, FWIW, is that configure will remember them when the configuration needs to be regenerated. That avoids problems such as #11657.

Is this problem new in OpenBSD 6.2? I've tried on 6.1 with my usual configure script, and found no issues;

./configure --with-gui=no --enable-experimental-asm CC=egcc CXX=eg++ CPP=ecpp BDB_LIBS="-L${BDB_PREFIX}/lib -ldb_cxx-4.8" BDB_CFLAGS="-I${BDB_PREFIX}/include"

However I can't try with 6.2 right now.

I am trying on 6.2, I haven't tried on 6.1.

I am familiar with autoconf and aware that passing them as command-line arguments should work in theory, I was surprised when it told me configure: error: C compiler cannot create executables. Interestingly enough, feeding them in as environment variables took care of it.

I've reproduced the problem on a new 6.2 install. The changes to the build commands do seem to fix the issue. This will also close #11868.

Can you please take a look here @theuni? Any idea what could cause this change to be necessary?

This seems to work on OpenBSD 6.2, to build using the built-in clang 4.0 (no need to install any compiler anymore):

./configure --disable-wallet CC=cc CXX=c++ CPP=cpp

So maybe this is only wallet related? The contrib/install_db4.sh script, unlike configure, very likely doesn't take X=Y pairs for arguments, and the build guide mentions doing that.

See #11945 (which should make these changes unnecessary)

ACK closing in favor of #11945.