[riscv][risc-v][riscv64]Cannot build Bazel 7.1.0 on RISC-V 64 (Lichee PI4A)

Description of the bug:

Hello,

I am running Ubuntu 24.04 stock (riscv64) on the LicheePi 4A.

When trying to build bazel from source (7.1.0), I get an error, as it weirdly tries to build Bazel with Bazel (?) and it fails.

My first question is: why is it trying to build Bazel with Bazel -> Building Bazel with Bazel?

Reproduction steps:

# download and unzip / cd into bazel-7.1.0-dist.zip
# apt install java 21 jre and jdk
# dpkg --list |grep -i jdk
# ii  default-jdk-headless                             2:1.21-75+exp1                            riscv64      Standard Java or Java compatible  Development Kit (headless)
#
# ii  libanimal-sniffer-java                           1.16-1                                    all          JDK/API verification tools
#ii  openjdk-21-jdk:riscv64                           21.0.3+9-1ubuntu1                         riscv64      OpenJDK Development Kit (JDK)
#ii  openjdk-21-jdk-headless:riscv64                  21.0.3+9-1ubuntu1                         riscv64      OpenJDK Development Kit (JDK) (headless)
#ii  openjdk-21-jre:riscv64                           21.0.3+9-1ubuntu1                         riscv64      OpenJDK Java runtime, using Hotspot JIT
#ii  openjdk-21-jre-headless:riscv64                  21.0.3+9-1ubuntu1                         riscv64      OpenJDK Java runtime, using Hotspot JIT (headless)

env EXTRA_BAZEL_ARGS="--tool_java_runtime_version=local_jdk" bash ./compile.sh
🍃  Building Bazel from scratch......
🍃  Building Bazel with Bazel.
.OpenJDK 64-Bit Server VM warning: Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release.
INFO: Repository rules_python~~python~pythons_hub instantiated at:
  <builtin>: in <toplevel>
Repository rule hub_repo defined at:
  /tmp/bazel_Jag75LiP/out/external/rules_python~/python/extensions/private/pythons_hub.bzl:107:27: in <toplevel>
ERROR: An error occurred during the fetch of repository 'rules_python~~python~pythons_hub':
   Traceback (most recent call last):
        File "/tmp/bazel_Jag75LiP/out/external/rules_python~/python/extensions/private/pythons_hub.bzl", line 86, column 33, in _hub_repo_impl
                platform = get_host_platform(os, arch)
        File "/tmp/bazel_Jag75LiP/out/external/rules_python~/python/private/toolchains_repo.bzl", line 325, column 13, in get_host_platform
                fail("No platform declared for host OS {} on arch {}".format(os_name, arch))
Error in fail: No platform declared for host OS linux on arch riscv64
ERROR: <builtin>: fetching hub_repo rule //:rules_python~~python~pythons_hub: Traceback (most recent call last):
        File "/tmp/bazel_Jag75LiP/out/external/rules_python~/python/extensions/private/pythons_hub.bzl", line 86, column 33, in _hub_repo_impl
                platform = get_host_platform(os, arch)
        File "/tmp/bazel_Jag75LiP/out/external/rules_python~/python/private/toolchains_repo.bzl", line 325, column 13, in get_host_platform
                fail("No platform declared for host OS {} on arch {}".format(os_name, arch))
Error in fail: No platform declared for host OS linux on arch riscv64

Which category does this issue belong to?

Core

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

No response

Which operating system are you running Bazel on?

No response

What is the output of bazel info release?

No response

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

No response

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

No response

If this is a regression, please try to identify the Bazel commit where the bug was introduced with bazelisk --bisect.

No response

Have you found anything relevant by searching the web?

No response

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

No response