node-gyp rebuild fails with python 3

[bjb568]

> node-gyp rebuild

gyp ERR! configure error 
gyp ERR! stack Error: Command failed: /anaconda3/bin/python -c import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack   File "<string>", line 1
gyp ERR! stack     import sys; print "%s.%s.%s" % sys.version_info[:3];
gyp ERR! stack                                ^
gyp ERR! stack SyntaxError: invalid syntax
gyp ERR! stack 
gyp ERR! stack     at ChildProcess.exithandler (child_process.js:294:12)
gyp ERR! stack     at ChildProcess.emit (events.js:189:13)
gyp ERR! stack     at maybeClose (internal/child_process.js:970:16)
gyp ERR! stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
gyp ERR! System Darwin 18.6.0
gyp ERR! command "/usr/local/bin/node" "/Users/myusername/.npm-packages/lib/node_modules/npm/node_modules/node-gyp/bin/node-gyp.js" "rebuild"
gyp ERR! cwd /Users/myusername/Desktop/crawl-compare/node_modules/abp-parser-v10/node_modules/bloom-filter-cpp
gyp ERR! node -v v10.15.3
gyp ERR! node-gyp -v v3.8.0
gyp ERR! not ok 
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! bloom-filter-cpp@1.2.2 install: `node-gyp rebuild`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the bloom-filter-cpp@1.2.2 install script.

I worked around this by making a conda environment for python 2, switching to it, then installing.