Unable to bootstrap Bazel on Z platform

[LakshmiRavichandran1]

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Description of the problem / feature request:

Unable to bootstrap Bazel on Z platform.
The instructions at https://docs.bazel.build/versions/main/install-compile-source.html#bootstrap-bazel has been followed.
The build fails with errors stating 'external/upb/upb/table.c:742:15: error: this statement may fall through [-Werror=implicit-fallthrough=]' .

Feature requests: what underlying problem are you trying to solve with this feature?

Successfully build Bazel from scratch on Z platform.

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

1. Get hold of a vm based on s390x architecture
2. Try to build bazel from scratch following https://docs.bazel.build/versions/main/install-compile-source.html#bootstrap-bazel.

The bazel distribution bazel-4.1.0-dist.zip at https://github.com/bazelbuild/bazel/releases/tag/4.1.0 was used in this case.
# wget https://github.com/bazelbuild/bazel/releases/download/4.1.0/bazel-4.1.0-dist.zip

What operating system are you running Bazel on?

Red Hat Enterprise Linux 8.3 (Ootpa).

#cat /etc/os-release
NAME="Red Hat Enterprise Linux"
VERSION="8.3 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.3"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.3 (Ootpa)"
ANSI_COLOR="0;31"

What's the output of bazel info release?

unable to fetch this info as bazel is not successfully built yet.

If bazel info release returns "development version" or "(@non-git)", tell us how you built Bazel.

unable to fetch this info as bazel is not successfully built yet.

What's the output of git remote get-url origin ; git rev-parse master ; git rev-parse HEAD ?

this information cannot be fetched as only a bazel distribution (bazel-4.1.0-dist.zip) was used to build it from scratch.

Have you found anything relevant by searching the web?

already reported issues or discussions on setting CFLAGS with --copt didnot help overcoming the problem.

Any other information, logs, or outputs that you want to share?

`# env EXTRA_BAZEL_ARGS="--host_javabase=@local_jdk//:jdk" bash ./compile.sh
🍃  Building Bazel from scratch......
🍃  Building Bazel with Bazel.
...
ERROR: /tmp/bazel_rOgBYs0z/out/external/upb/BUILD:78:11: Compiling upb/table.c failed: (Exit 1): gcc failed: error executing command 
  (cd /tmp/bazel_rOgBYs0z/out/execroot/io_bazel && \
  exec env - \
    PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin \
    PWD=/proc/self/cwd \
  /usr/bin/gcc -U_FORTIFY_SOURCE -fstack-protector -Wall -Wunused-but-set-parameter -Wno-free-nonheap-object -fno-omit-frame-pointer -g0 -O2 '-D_FORTIFY_SOURCE=1' -DNDEBUG -ffunction-sections -fdata-sections -MD -MF bazel-out/s390x-opt/bin/external/upb/_objs/upb/table.d '-frandom-seed=bazel-out/s390x-opt/bin/external/upb/_objs/upb/table.o' -iquote external/upb -iquote bazel-out/s390x-opt/bin/external/upb -Wextra -Werror -Wno-long-long -pedantic '-Werror=pedantic' -Wstrict-prototypes -fno-canonical-system-headers -Wno-builtin-macro-redefined '-D__DATE__="redacted"' '-D__TIMESTAMP__="redacted"' '-D__TIME__="redacted"' -c external/upb/upb/table.c -o bazel-out/s390x-opt/bin/external/upb/_objs/upb/table.o)
Execution platform: //:default_host_platform
external/upb/upb/table.c: In function 'upb_murmur_hash2':
external/upb/upb/table.c:742:15: error: this statement may fall through [-Werror=implicit-fallthrough=]
     case 3: h ^= data[2] << 16;
             ~~^~~~~~~~~~~~~~~~
external/upb/upb/table.c:743:5: note: here
     case 2: h ^= data[1] << 8;
     ^~~~
external/upb/upb/table.c:743:15: error: this statement may fall through [-Werror=implicit-fallthrough=]
     case 2: h ^= data[1] << 8;
             ~~^~~~~~~~~~~~~~~
external/upb/upb/table.c:744:5: note: here
     case 1: h ^= data[0]; h *= m;
     ^~~~
cc1: all warnings being treated as errors
Target //src:bazel_nojdk failed to build
INFO: Elapsed time: 129.984s, Critical Path: 13.76s
INFO: 608 processes: 17 internal, 591 local.
FAILED: Build did NOT complete successfully

ERROR: Could not build Bazel

# g++ --version
g++ (GCC) 8.3.1 20191121 (Red Hat 8.3.1-5)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

# java -showversion
openjdk version "1.8.0_265"
OpenJDK Runtime Environment (build 1.8.0_265-b01)
OpenJDK 64-Bit Zero VM (build 25.265-b01, interpreted mode)`

[cfilleke]

Hi Lakshmi!

try this build command for bootstrapping bazel:

env EXTRA_BAZEL_ARGS="--show_progress_rate_limit=0 --show_task_finish --show_timestamps --worker_verbose --color=no --copt="-Wno-error=implicit-fallthrough"  --curses=yes --host_javabase=@local_jdk//:jdk" bash ./compile.sh &> build.log

• the --copt="Wno-error=implicit-fallthrough" tells the C compiler to please not turn warnings into fatal errors when the warning concerns implicit fallthroughs (as used in murmur-hash functions that seem to be copied-and-pasted and sometimes modified in about 12 places throughout the code)
• the other additional options give you a build log you can analyze, debug and store a little easier than the default "now you see it now you don't" bazel build output.
• NB I am still a little dubious about the implementation of murmur-hash as written on big endian machines, but that is a different discussion.

[github-actions]

Thank you for contributing to the Bazel repository! This issue has been marked as stale since it has not had any activity in the last 1+ years. It will be closed in the next 90 days unless any other activity occurs. If you think this issue is still relevant and should stay open, please post any comment here and the issue will no longer be marked as stale.

[github-actions]

This issue has been automatically closed due to inactivity. If you're still interested in pursuing this, please post @bazelbuild/triage in a comment here and we'll take a look. Thanks!