When a Go command will not finish, the question is whether it is genuinely slow or silently blocked on input, and Atlas's bash tool answers it. Atlas races every command against a timeout and, when the timeout expires, tells you exactly what happened and what to do: retry with a larger timeout if the command is expected to take longer and is not waiting for interactive input. That second clause is the diagnosis. A go mod download blocked on a credential prompt for a private module never resolves by waiting, while a cold go test on a large module genuinely needs more milliseconds.
Why does my go test hang forever under an AI coding agent?
A go test that hangs under an AI coding agent in 2026 has two causes, and they need opposite responses. The command is either genuinely slow, in which case a larger timeout fixes it, or blocked on stdin, in which case waiting never helps. Atlas's bash tool races every command against a timeout and reports which case you are in.
The blocked case is the common one and the one people misdiagnose. A go mod download against a private module can stop dead waiting for git to prompt for credentials. A generator or a migration tool invoked from a Go build script can stop waiting for a yes or no confirmation. In a normal terminal you would see the prompt and answer it. Under an agent there is no human on that stdin, so the process waits forever and looks identical to a slow compile. Atlas's timeout message is what breaks the tie, because it explicitly calls out the interactive-input case rather than just reporting that time ran out.
What does the shell_metadata block tell me when Atlas kills a Go command?
The shell_metadata block in Atlas's bash output is where a killed Go command explains itself in 2026. Atlas does not just say the command timed out. It tells you what happened and what to do: retry with a larger timeout if the command is expected to take longer and is not waiting for interactive input.
The wording of that message is the diagnostic instrument. It gives a condition, not just an outcome, so a Go developer reading it has to answer a real question: is my go build actually expected to take longer than the timeout, and is it definitely not waiting for input? If the answer is yes to both, a larger timeout in milliseconds is the fix. If go test on a package with 40 test files has always finished in seconds and suddenly does not, the timeout is not the problem and raising it just wastes another minute. Atlas's bash metadata also distinguishes a third case: if you aborted it yourself, the metadata says User aborted the command, so your interrupt is never confused with a timeout.
How do I stop a Go command from blocking on interactive input?
Re-run the Go command with the tool's non-interactive flags, such as -y, --no-input, or a CI mode. In 2026 a Go toolchain invocation that stops for a credential prompt or a confirmation will stop again the next time unless it is told, explicitly, that no human is present on stdin.
The concrete Go cases are worth knowing. A go mod download or go mod tidy that touches a private module can block on a git credential prompt, so configure the credentials non-interactively before the run. A code generator invoked from a go:generate directive can block on a confirmation, so pass its non-interactive flag. A migration or seeding step in a Makefile that a Go integration test depends on can block the same way. Re-running through Atlas's bash tool with the non-interactive flag turns a silent hang into either a success or a loud error, and a loud error is progress.
How do I give a genuinely slow Go build a larger timeout in Atlas?
Give a slow Go build more room by retrying with a larger timeout value in milliseconds, exactly as the Atlas message instructs. In 2026 a cold go build on a large module with a fresh module cache, or a go test run that includes integration packages, can legitimately exceed a default timeout without being stuck at all.
The judgment call is whether slow is honest. A Go build that has to download and compile every dependency in go.sum for the first time is honestly slow, and so is a go test invocation that spins up containers for integration packages. Both deserve a bigger timeout in milliseconds. What does not deserve one is a command that has never taken this long before, because a sudden change in duration is a symptom, not a workload. Atlas's message asks you to confirm the command is expected to take longer and is not waiting for interactive input before you raise the number, and that ordering is the whole discipline.
How does Atlas tell my interrupt apart from a timeout on a Go command?
In 2026 Atlas records an abort separately from a timeout on any Go command. If you stopped go test yourself, the shell_metadata says User aborted the command, so your interrupt is never misread as a hang that sends you chasing a nonexistent deadlock in your own code.
That distinction sounds small and matters a lot in practice, because the two look identical from the outside: a partially printed output and no exit. If a killed go test were always reported as a timeout, an agent would conclude that the package hangs and start hunting for a blocked channel or a missing WaitGroup Done. The User aborted the command metadata prevents that entire wasted branch. Every Atlas tool call is permission-gated against allow, ask, and deny rules before it runs, so you always have the option to deny or abort a long Go command, and the record of doing so is unambiguous.
How do I set Atlas up on a Go module before diagnosing a hang?
Run atlas in a module with a go.mod. In 2026 Atlas reads your packages, interfaces, and go.sum dependencies, which is the context that lets it tell you whether a slow go build is downloading dependencies for the first time or whether a go test package is doing something it never did before.
The go.mod and go.sum are the files that explain most honest slowness in a Go project: a fresh module cache means every listed dependency is fetched and compiled before your code even builds. With the module loaded, the bash tool's timeout behavior becomes a diagnostic rather than an obstacle, and the read tool lets you inspect the Makefile or the go:generate directive that invoked the blocking subprocess. Keep gofmt in the loop for any fix you make to a build script or a test helper, so the diff shows the behavioral change and nothing else.
Step by step
- 01Run atlas in a Go module with a go.mod so Atlas reads your packages, interfaces, and go.sum dependencies.
- 02Run the command, for example go test or go mod download, through the bash tool and read the shell_metadata block in the output when it is killed.
- 03Decide from the message whether the command is slow or blocked: Atlas explicitly calls out the interactive-input case rather than only reporting that time ran out.
- 04If it is blocked, re-run with the tool's non-interactive flags (-y, --no-input, CI mode) so it cannot prompt; a go mod download against a private module commonly blocks on a git credential prompt.
- 05If it is genuinely slow, retry with a larger timeout value in milliseconds, as the message instructs, which is the right call for a cold go build that must fetch every dependency in go.sum.
- 06If you aborted it yourself, note that the metadata says User aborted the command, which distinguishes your interrupt from a timeout and stops you hunting for a deadlock that does not exist.
- 07Read the Makefile or go:generate directive with the read tool when the blocking process was invoked indirectly by the Go build.
- 08Run gofmt on any fix you make to a build script or test helper so the diff shows the behavioral change and not formatting.
Frequently asked questions
- why does go mod download hang when run by an AI coding agent
- Usually because it is blocked on stdin, not because it is slow. A go mod download against a private module can stop waiting for a git credential prompt, and there is no human on that stdin under an agent. Atlas's bash timeout message explicitly calls out the interactive-input case, so re-run with credentials configured non-interactively.
- how do I tell whether a go build is slow or stuck
- Read the shell_metadata block in Atlas's bash output when the command is killed. Atlas tells you to retry with a larger timeout if the command is expected to take longer and is not waiting for interactive input. If the build has never taken this long before, the duration is a symptom and a bigger timeout will not help.
- how do I increase the command timeout in Atlas
- Retry with a larger timeout value in milliseconds, as the timeout message instructs. That is the right response for a cold go build that must download and compile every dependency in go.sum, or a go test run that includes integration packages.
- what does User aborted the command mean in Atlas
- It means you interrupted the command yourself, and Atlas records that in the shell_metadata rather than reporting a timeout. That distinction matters in Go, because an aborted go test misread as a hang sends you hunting for a blocked channel or a missing WaitGroup Done that does not exist.
- how do I stop a command from prompting for input under an agent
- Re-run it with the tool's non-interactive flags, such as -y, --no-input, or a CI mode, so it cannot prompt at all. That turns a silent hang into either a success or a loud error, and a loud error is progress.
- does Atlas kill long running Go commands automatically
- Atlas's bash tool races every command against a timeout, and when the timeout expires it reports what happened and what to do. It is not a blanket refusal to run long commands: a genuinely slow go test just needs a larger timeout value in milliseconds.
- does Atlas need go.mod to diagnose a hanging command
- Run atlas in a module with a go.mod so Atlas reads your packages, interfaces, and go.sum dependencies. That context is what explains most honest slowness in a Go project, since a fresh module cache means every listed dependency is fetched and compiled before your code builds.
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Install AtlasRelated guides
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