Describe the bug

When building from source with BSD sed, following error happens:

./src/version.h:1:1: error: unknown type name 'x23define'
x23define JQ_VERSION "1.8.0"

I think the bug was brought by

If we change \x23 to \# everything works fine.

To Reproduce

Build with BSD sed, like /usr/bin/sed on macOS.

Expected behavior

Build successfully.

Environment (please complete the following information):

• OS and Version: macOS
• jq version 1.8

Additional context