[C++] Build failures with glog enabled

[asfimport]

This has started appearing on Travis, e.g.:
https://travis-ci.org/apache/arrow/jobs/596181386#L3663

In file included from /home/travis/build/apache/arrow/cpp/src/arrow/util/logging.cc:29:0:

/home/travis/build/apache/arrow/pyarrow-test-3.6/include/glog/logging.h:994:0: error: "DCHECK" redefined [-Werror]

 #define DCHECK(condition) CHECK(condition)

 

In file included from /home/travis/build/apache/arrow/cpp/src/arrow/util/logging.cc:18:0:

/home/travis/build/apache/arrow/cpp/src/arrow/util/logging.h:130:0: note: this is the location of the previous definition

 #define DCHECK ARROW_CHECK

 

Reporter: Antoine Pitrou / @pitrou

PRs and other links:

• GitHub Pull Request #5620

_{Note: This issue was originally created as ARROW-6846. Please see the migration documentation for further details.}

[asfimport]

Antoine Pitrou / @pitrou:
It was a problem with conda-forge compilers, fixed in conda-forge/ctng-compiler-activation-feedstock#3