And got this result:

$ cd /gnu/store/rdwyr8mh7dvhfkb5g4cws6q40hp23rbi-bootstrap-tarballs-0
$ sha256sum *
3e50c070a100b6bcf84c4bf5c868f9cd0a9fd1570f5d82fbfb78f8411959091b  guile-static-stripped-2.2.4-i686-linux.tar.xz
1acd8f83e27d2fac311a5ca78e9bf11a9a1638b82469870d5c854c4e7afaa26a  linux-libre-headers-stripped-4.14.67-i686-linux.tar.xz
021543d9bb6af55f39e68d69692e3cb74646ced2cad0bb9ac0047ef81e9d7330  mescc-tools-static-stripped-0.5.2-i686-linux.tar.xz
fb32090071b39fc804fb9a7fba96f0bc5eb844a0efd268fb24c42e6bfa959de0  mes-minimal-stripped-0.19-i686-linux.tar.xz
c80cdd17b0a24eebdd75570ff72c4ec06e129bd702ac008186b57f6301c448e7  static-binaries-0-i686-linux.tar.xz

I also merged the branch to core-updates and reverted the bash patch,
which produced this derivation for "guix build -d -s i686-linux
bootstrap-tarballs":

/gnu/store/ld82vli1msfrlimjaryznrqcwm0jc5ii-bootstrap-tarballs-0.drv

I will report back with hashes once it finishes building.  It would be
great if someone else could try to resolve the merge and see if they get
the same derivation.