stamping with build information. Obviously, replace _slash_ in the filenames with an actual slash!

bi.py

from pprint import pprint
import buildinfo
pprint(buildinfo.buildinfo)

BUILD

package(default_visibility = ["//visibility:public"])

genrule(
  name = "genpybuildinfo",
  outs = [
    "buildinfo.py",
  ],
  stamp = 1,
  cmd = "./$(location tools/mkpybuildinfo.sh) > \"$@\"",
  tools = [
    "tools/mkpybuildinfo.sh",
  ],
)

py_library(
  name = "buildinfo",
  srcs = [
    ":genpybuildinfo",
  ],
)

# Use this for testing, remove in production!
py_binary(
  name = "bi",
  srcs = [
    "bi.py",
  ],
  deps = [
    ":buildinfo",
  ],
)

tools_slash_bazel.rc

build --workspace_status_command=./tools/mkstamp.sh

tools_slash_mkpybuildinfo.sh

#!/bin/sh
cat << @EOF
_status = '''
$(cat bazel-out/stable-status.txt bazel-out/volatile-status.txt)
'''
buildinfo = dict()
for l in _status.splitlines():
  ll = l.strip().split(None, 1)
  if len(ll) == 2:
    buildinfo[ll[0]] = ll[1]

tools_slash_mkstamp.sh

#!/bin/sh
echo BUILD_DATE $(TZ=Etc/UTC date -Iseconds)
echo BUILD_SCM_HASH $(git rev-parse HEAD)