Fail to build on Linux due to 404 from mirror.bazel.build

[xuxinhang]

I'm trying to build carbon-lang following the guide of README, but replace brew with apt on my Ubuntu 18.04 LTS.

The bazelisk is downloaded from the latest GitHub release and added to PATH manually. llvm (and clang) are installed via apt. Soon after launching building, bazel complained unable to download packages, followed by errors issued:

INFO: Invocation ID: 9849c062-82bd-4aba-b144-8d546424cfec
WARNING: Download from https://mirror.bazel.build/ftp.gnu.org/gnu/m4/m4-1.4.18.tar.xz failed: class java.io.FileNotFoundException GET returned 404 Not Found
WARNING: Download from https://mirror.bazel.build/github.com/jmillikin/rules_m4/releases/download/v0.1/m4-gnulib-788db09a9f88abbef73c97e8d7291c40455336d8.tar.xz failed: class java.io.FileNotFoundException GET returned 404 Not Found
WARNING: Download from https://mirror.bazel.build/ftp.gnu.org/gnu/bison/bison-3.3.2.tar.xz failed: class java.io.FileNotFoundException GET returned 404 Not Found
WARNING: Download from https://mirror.bazel.build/github.com/jmillikin/rules_bison/releases/download/v0.1/bison-gnulib-788db09a9f88abbef73c97e8d7291c40455336d8.tar.xz failed: class java.io.FileNotFoundException GET returned 404 Not Found
INFO: Analyzed target //explorer:explorer (0 packages loaded, 0 targets configured).
INFO: Found 1 target...
ERROR: /home/li/.cache/bazel/_bazel_li/0228db5d83e20d51b81b9fb458bad627/external/m4_v1.4.18/gnulib/BUILD.bazel:193:11: Compiling gnulib/lib/sig-handler.c [for host] failed: undeclared inclusion(s) in rule '@m4_v1.4.18//gnulib:gnulib':
this rule is missing dependency declarations for the following files included by 'gnulib/lib/sig-handler.c':
  '/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stddef.h'
ERROR: /home/li/.cache/bazel/_bazel_li/0228db5d83e20d51b81b9fb458bad627/external/m4_v1.4.18/gnulib/BUILD.bazel:193:11: Compiling gnulib/lib/secure_getenv.c [for host] failed: undeclared inclusion(s) in rule '@m4_v1.4.18//gnulib:gnulib':
this rule is missing dependency declarations for the following files included by 'gnulib/lib/secure_getenv.c':
  '/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stddef.h'
ERROR: /home/li/.cache/bazel/_bazel_li/0228db5d83e20d51b81b9fb458bad627/external/m4_v1.4.18/gnulib/BUILD.bazel:193:11: Compiling gnulib/lib/fpending.c [for host] failed: undeclared inclusion(s) in rule '@m4_v1.4.18//gnulib:gnulib':
this rule is missing dependency declarations for the following files included by 'gnulib/lib/fpending.c':
  '/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stddef.h'
  '/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stdarg.h'
Target //explorer:explorer failed to build
Use --verbose_failures to see the command lines of failed build steps.
INFO: 7 processes: 7 internal.
FAILED: Build did NOT complete successfully

The URLs given by the log does return HTTP 404.

How can I solve this problem? Should I switch to another Bazel version?

[jonmeow]

The mirror issues are warnings, not errors. The first error is here:

ERROR: /home/li/.cache/bazel/_bazel_li/0228db5d83e20d51b81b9fb458bad627/external/m4_v1.4.18/gnulib/BUILD.bazel:193:11: Compiling gnulib/lib/sig-handler.c [for host] failed: undeclared inclusion(s) in rule '@m4_v1.4.18//gnulib:gnulib':
this rule is missing dependency declarations for the following files included by 'gnulib/lib/sig-handler.c':
  '/usr/lib/llvm-6.0/lib/clang/6.0.0/include/stddef.h'

From this, I can observe that you're using a system install of LLVM v6. This is old, and also doesn't match our install advice.

Please see: https://github.com/carbon-language/carbon-lang/blob/trunk/docs/project/contribution_tools.md#troubleshooting-build-issues