build: better error message on python fail
Fixes: https://github.com/nodejs/node/issues/16864 Refs: https://github.com/nodejs/node/pull/17293
On a machine without python installed:
d:\code\node$ vcbuild
Could not find python2. More information can be found at
https://github.com/nodejs/node/blob/master/BUILDING.md#windows-1
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
documentation is changed or added -
commit message follows commit guidelines
Affected core subsystem(s)
build,windows,tools