x/build: linux-riscv64 builder too slow to run racebuild

[prattmic]

I am creating new race sysos for #78059 using racebuild. Unfortunately, I've been unable to build for riscv64 because it takes so long that something times out before it completes.

It looks like the immediate problem is perhaps the network connection being extremely slow. It mostly gets stuck attempting to clone the Go repo. On one attempt it did succeed with Go, only to time out downloading LLVM.

I think the timeouts are gomote (temporarily?) losing connection to the builder.

For now I will skip updating the openbsd race sysos.

One example run:

$ go run ./cmd/racebuild -goroot ~/src/go -rev c3c24be13f7928460ca1e2fe613a1146c868854e -llvm-patch ~/Downloads/llvm/llvm.patch -gorev a61fd428974822a8c57a2b2840fc237e6711b24d -platforms linux/riscv64 -copyonfail
2026/03/20 11:19:14 using Go revision: a61fd428974822a8c57a2b2840fc237e6711b24d
2026/03/20 11:19:14 linux/riscv64: gomote [create -status=false gotip-linux-riscv64]
mpratt-gotip-linux-riscv64-0
2026/03/20 11:25:15 linux/riscv64: gomote [create -status=false gotip-linux-riscv64] succeeded:
mpratt-gotip-linux-riscv64-0
2026/03/20 11:25:15 linux/riscv64: using instance mpratt-gotip-linux-riscv64-0
2026/03/20 11:25:15 linux/riscv64: gomote [putbootstrap mpratt-gotip-linux-riscv64-0]
2026/03/20 11:25:15 linux/riscv64: gomote [putbootstrap mpratt-gotip-linux-riscv64-0] succeeded: <no output>
2026/03/20 11:25:15 linux/riscv64: gomote [put -mode=0700 mpratt-gotip-linux-riscv64-0 /tmp/racebuild3113345916 script.bash]
2026/03/20 11:25:17 linux/riscv64: gomote [put -mode=0700 mpratt-gotip-linux-riscv64-0 /tmp/racebuild3113345916 script.bash] succeeded: <no output>
2026/03/20 11:25:17 linux/riscv64: gomote [put -mode=0600 mpratt-gotip-linux-riscv64-0 /usr/local/google/home/mpratt/Downloads/llvm/llvm.patch patch.patch]
2026/03/20 11:25:19 linux/riscv64: gomote [put -mode=0600 mpratt-gotip-linux-riscv64-0 /usr/local/google/home/mpratt/Downloads/llvm/llvm.patch patch.patch] succeeded: <no output>
2026/03/20 11:25:19 linux/riscv64: gomote [run -e=REV=c3c24be13f7928460ca1e2fe613a1146c868854e -e=GOREV=a61fd428974822a8c57a2b2840fc237e6711b24d -e=GOGITOP= -e=GOSRCREF= -e=LLVM_PATCH=1 mpratt-gotip-linux-riscv64-0 script.bash]
# Streaming results from "mpratt-gotip-linux-riscv64-0" to "/tmp/gomote1310130024/mpratt-gotip-linux-riscv64-0.stdout"...
Linux milkv-megrez-1 6.6.88-win2030 #2025.08.14.16.08+bf2ec5d53 SMP Thu Aug 14 16:24:14 UTC 2025 riscv64 GNU/Linux
PRETTY_NAME="Debian GNU/Linux trixie/sid"
NAME="Debian GNU/Linux"
VERSION_CODENAME=trixie
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
正克隆到 'go'...
# Wrote results from "mpratt-gotip-linux-riscv64-0" to "/tmp/gomote1310130024/mpratt-gotip-linux-riscv64-0.stdout".
# Error running run: unable to execute script.bash: rpc error: code = Unavailable desc = error reading from server: read tcp 100.65.40.245:56116->35.244.221.129:443: read: connection timed out
2026/03/20 13:38:17 linux/riscv64: gomote [run -e=REV=c3c24be13f7928460ca1e2fe613a1146c868854e -e=GOREV=a61fd428974822a8c57a2b2840fc237e6711b24d -e=GOGITOP= -e=GOSRCREF= -e=LLVM_PATCH=1 mpratt-gotip-linux-riscv64-0 script.bash] failed:
# Streaming results from "mpratt-gotip-linux-riscv64-0" to "/tmp/gomote1310130024/mpratt-gotip-linux-riscv64-0.stdout"...
Linux milkv-megrez-1 6.6.88-win2030 #2025.08.14.16.08+bf2ec5d53 SMP Thu Aug 14 16:24:14 UTC 2025 riscv64 GNU/Linux
PRETTY_NAME="Debian GNU/Linux trixie/sid"
NAME="Debian GNU/Linux"
VERSION_CODENAME=trixie
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"
正克隆到 'go'...
# Wrote results from "mpratt-gotip-linux-riscv64-0" to "/tmp/gomote1310130024/mpratt-gotip-linux-riscv64-0.stdout".
# Error running run: unable to execute script.bash: rpc error: code = Unavailable desc = error reading from server: read tcp 100.65.40.245:56116->35.244.221.129:443: read: connection timed out
2026/03/20 13:38:17 linux/riscv64: gomote script run failed, continuing...
2026/03/20 13:38:17 linux/riscv64: gomote [gettar -dir=outdir mpratt-gotip-linux-riscv64-0]
# Downloading tarball for "mpratt-gotip-linux-riscv64-0" to "mpratt-gotip-linux-riscv64-0.tar.gz"...
# Error running gettar: unable to retrieve tgz URL: rpc error: code = NotFound desc = specified gomote instance does not exist
2026/03/20 13:38:18 linux/riscv64: gomote [gettar -dir=outdir mpratt-gotip-linux-riscv64-0] failed:
# Downloading tarball for "mpratt-gotip-linux-riscv64-0" to "mpratt-gotip-linux-riscv64-0.tar.gz"...
# Error running gettar: unable to retrieve tgz URL: rpc error: code = NotFound desc = specified gomote instance does not exist
2026/03/20 13:38:18 linux/riscv64: gomote [destroy mpratt-gotip-linux-riscv64-0]
# Destroying mpratt-gotip-linux-riscv64-0
# Error running destroy: unable to destroy instance: rpc error: code = NotFound desc = specified gomote instance does not exist
2026/03/20 13:38:18 linux/riscv64: gomote [destroy mpratt-gotip-linux-riscv64-0] failed:
# Destroying mpratt-gotip-linux-riscv64-0
# Error running destroy: unable to destroy instance: rpc error: code = NotFound desc = specified gomote instance does not exist
2026/03/20 13:38:18 linux/riscv64 failed: exit status 1
exit status 1

cc @golang/riscv64

[mengzhuo]

Looks like a flaky network issue to me, could you send me the patch I can build it for you

[prattmic]

The patch is in https://go.dev/cl/757521 (all of the .patch files are identical). Though historically we have tried to ensure we can reproduce the built syso, so it's better if we can fix the builder.

[mengzhuo]

Hi @prattmic Can you rerun by yourself, I had improve the network condition for riscv64 builders.