[build2] "Backwards modification times" in 0.9.0

[Per Edin]

Hi!

I'm trying to install build2 0.9.0 from stage.build2.org/0/
(build2-toolchain-0.9.0-a.0.20181116172606.63932750d8ec) on macOS, but
I'm receiving errors about backwards modification times.

ar ../libbutl/libbutl/liba{butl}
error: backwards modification times:
/Users/per/work/build2-toolchain-0.9.0-a.0.20181116172606.63932750d8ec/libbutl/libbutl/libbutl.a.d
2018-11-16 23:31:39.498914000 (0)
/Users/per/work/build2-toolchain-0.9.0-a.0.20181116172606.63932750d8ec/libbutl/libbutl/libbutl.a
  2018-11-16 23:31:39
2018-11-16 23:31:39.498867000
2018-11-16 23:31:39.554364000
  info: while updating ../libbutl/libbutl/liba{butl}
  info: while updating build2/libue{b}
  info: while updating build2/exe{b}

ar ../libpkgconf/libpkgconf/liba{pkgconf}
error: backwards modification times:
/Users/per/work/build2-toolchain-0.9.0-a.0.20181116172606.63932750d8ec/libpkgconf/libpkgconf/libpkgconf.a.d
2018-11-16 23:31:40.231143000 (0)
/Users/per/work/build2-toolchain-0.9.0-a.0.20181116172606.63932750d8ec/libpkgconf/libpkgconf/libpkgconf.a
  2018-11-16 23:31:40
2018-11-16 23:31:40.231084000
2018-11-16 23:31:40.259055000
  info: while updating ../libpkgconf/libpkgconf/liba{pkgconf}
  info: while updating build2/libue{b}
  info: while updating build2/exe{b}

Any ideas why this is happening? My date and time is set correctly.
The same script worked fine inside a Docker container
(debian:stretch-backports).

Kind regards,
Per Edin