The Final Deployment: Verifying a Production Fix Through Binary Hashes and Version Strings

In the high-stakes world of distributed GPU proving systems, deploying a fix to production is rarely as simple as merging a pull request. Message [msg 1992] captures the culmination of a multi-hour debugging session that traced a catastrophic production bug—where all ten PoRep partitions were producing invalid proofs—to a deceptively simple root cause: a job ID collision in concurrent proofshare challenges. The message itself is a single bash command, but it represents the moment when weeks of debugging, multiple binary rebuilds, and iterative deployments finally converge on a verified fix.

The Message

The assistant executes:

ssh -p 40362 root@141.195.21.72 'mv /tmp/curio-psfix2 /usr/local/bin/curio && chmod +x /usr/local/bin/curio && md5sum /usr/local/bin/curio && curio --version 2>&1'

And receives back:

ebf430967e85db6e767539edc04aa4f7  /usr/local/bin/curio
curio version 1.27.3-rc2+mainnet+git_96f6c783_2026-03-11T16:08:33+01:00_psfix2

This is not a complex command. It moves a binary, makes it executable, computes its MD5 hash, and prints the version string. Yet in the context of the preceding hours, this output represents a hard-won victory.

The Debugging Journey That Led Here

To understand why this simple deployment command matters, we must trace the debugging arc that preceded it. The user had deployed a proofshare system where concurrent challenges from cusvc/powsrv all targeted the same sector—miner=1000, sector=1—because these were benchmark sectors. Every concurrent PSProve task generated an identical job_id: ps-porep-1000-1. The cuzk engine's JobTracker used this job_id as a key in its assemblers HashMap, meaning that when multiple proofs ran in parallel, their partition results collided and overwrote each other. The result was catastrophic: all ten partitions produced invalid proofs, confirmed by a "partition 0 already inserted" panic in the Rust pipeline code and a verification result of 0/10 valid partitions.

The user had already identified the core issue in [msg 1977]: "possibly some pipeline partition keying issue, where the keys need to be more unique like request uuid?" The assistant confirmed the diagnosis in [msg 1978], noting that the snap path already included taskID in the request ID but the porep path did not. The fix was straightforward: change the format string from ps-porep-%d-%d to ps-porep-%d-%d-%d by threading the harmony task ID through the computePoRep call chain.

Why This Message Was Written

Message [msg 1992] exists because the first deployment attempt failed. In [msg 1991], the assistant checked the deployed binary and found it still showed version _psfix instead of _psfix2, and the running process was still the old curio-old-proofshare binary. The mv commands in the previous deployment had failed silently—likely because the running process locked the file, preventing the rename from succeeding. The binary size (170MB) matched the old binary, not the newly built 163MB binary. The deployment had not actually taken effect.

This message is therefore a corrective deployment. The assistant learned from the previous failure and adopted a cleaner approach: first kill the old process (done in the tail of [msg 1991]), then move the new binary into place, verify its hash, and confirm the version string. The explicit md5sum and curio --version commands are not decorative—they are the assistant's verification that the fix is genuinely compiled into the running binary.

Input Knowledge Required

To understand this message, one needs to know several things. First, the architecture of the proofshare system: that job_id is derived from minerid-sectorid, that challenge sectors are all identical in benchmark mode, and that the cuzk engine uses job_id as a HashMap key for partition assembly. Second, the build pipeline: that the binary was built inside a Docker container using curio-builder:latest with CUDA and supraseal support, and that the version string is injected via -X ldflags at build time. Third, the deployment workflow: that binaries are copied from the container to the host via docker cp and scp, and that the running process must be stopped before the binary can be replaced. Fourth, the significance of the version tag: _psfix2 indicates this is the second iteration of the proofshare fix, containing both the job ID uniqueness change and the earlier deadlock fix for HTTP 429 retries.

Output Knowledge Created

This message produces three critical pieces of output knowledge. First, the MD5 hash ebf430967e85db6e767539edc04aa4f7 provides a fingerprint that can be compared against future builds to confirm binary identity. Second, the version string _psfix2 confirms that the ldflags were correctly injected during the Docker build, meaning the source code change to the RequestId format string is present in the binary. Third, the absence of error output from the mv and chmod commands confirms that the file operations succeeded—a non-trivial achievement given the previous silent failure.

Assumptions and Potential Mistakes

The assistant makes several assumptions in this message. It assumes that the curio-psfix2 binary in /tmp on the remote host is the correct build—the one containing the ps-porep-%d-%d-%d format string. This assumption is supported by the Docker build output in [msg 1987], which used the modified source files. It assumes that the version string _psfix2 is a reliable indicator of the fix's presence, which is reasonable given that the ldflags are set during the same build invocation. However, there is a subtle risk: the version string only confirms that the build was performed with the _psfix2 tag, not that the specific source code change is present. A build cache issue could theoretically produce a binary with the correct version tag but stale object files—exactly the problem that plagued the earlier Dockerfile.cuzk-rebuild path in [msg 1976].

The assistant also assumes that the MD5 hash uniquely identifies the binary content. While true in principle, the hash alone does not prove the fix works—it only proves the binary is the same one that was built. The actual proof of correctness will come from running the proofshare system and observing valid proofs.

The Thinking Process Visible in the Message

The thinking process behind this message is visible primarily through what it does not do compared to the previous attempt. In [msg 1989], the assistant attempted a chained command: kill $PID; sleep 2; mv ... && mv ... && chmod ... && curio --version. This failed because the running process locked the file during the mv. In [msg 1992], the assistant separates the concerns: the kill was already performed in [msg 1991], and the deployment is a clean mv onto a stopped process. The addition of md5sum is also a learned behavior—in [msg 1991], the assistant relied solely on ls -la and the version string, which were misleading because the old binary was still in place. The hash provides an unambiguous identifier.

The version string check is particularly telling. The assistant could have simply trusted that the mv succeeded, but the previous failure taught it that silent failures are possible. By explicitly printing the version, the assistant confirms that the binary responds correctly and contains the expected build metadata. The Error parsing language line that appears before the version output is a benign artifact of the remote environment's locale settings, not a sign of failure.

The Broader Significance

This message exemplifies the operational rigor required when patching GPU-proving systems in production. Unlike a typical web service where a rolling restart suffices, these systems involve GPU state, parameter caches measured in gigabytes, and complex multi-phase proving pipelines where a single corrupted partition can invalidate an entire proof. The assistant's methodical approach—kill the process, replace the binary, verify the hash, check the version, then restart—reflects an understanding that silent corruption in this domain has outsized consequences.

The message also highlights the friction of patching systems built with heterogeneous toolchains. The Go binary is built inside a Docker container with CUDA libraries, then extracted and deployed to a bare-metal host. The build cache can produce stale binaries even when source files are updated, as happened with the Dockerfile.cuzk-rebuild path. The version string, injected via ldflags at build time, becomes a critical trust mechanism—the only way to confirm that the deployed binary actually contains the intended fix without running it against live data.

In the end, message [msg 1992] is about trust. The assistant cannot directly inspect the binary's source code on the remote host. It cannot run the proofshare system in a staging environment. It can only verify through indirect means—hashes, version strings, and careful observation of deployment commands—that the fix is in place. When the hash matches and the version reads _psfix2, the assistant has done everything possible to ensure the deployment is correct. The rest is up to the proving pipeline.