{"record":{"id":"7df62126876dd999","repo":"multica-ai/multica","slug":"chmod-temp-for-s-w","errorCode":null,"errorMessage":"chmod temp for %s: %w","messagePattern":"chmod temp for (.+?): %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"server/internal/daemon/execenv/hermes_home.go","lineNumber":927,"sourceCode":"\n// writeFileAtomic writes data to a temp file in the destination directory with\n// the given perms, then renames it over dst — so readers never see a partial\n// file and a prior file's looser permissions are replaced.\nfunc writeFileAtomic(dst string, data []byte, perm os.FileMode) error {\n\tdir := filepath.Dir(dst)\n\ttmp, err := os.CreateTemp(dir, \".hermes-tmp-*\")\n\tif err != nil {\n\t\treturn fmt.Errorf(\"create temp for %s: %w\", dst, err)\n\t}\n\ttmpName := tmp.Name()\n\tdefer os.Remove(tmpName) // no-op once renamed\n\tif _, err := tmp.Write(data); err != nil {\n\t\ttmp.Close()\n\t\treturn fmt.Errorf(\"write temp for %s: %w\", dst, err)\n\t}\n\tif err := tmp.Chmod(perm); err != nil {\n\t\ttmp.Close()\n\t\treturn fmt.Errorf(\"chmod temp for %s: %w\", dst, err)\n\t}\n\tif err := tmp.Close(); err != nil {\n\t\treturn fmt.Errorf(\"close temp for %s: %w\", dst, err)\n\t}\n\tif err := os.Rename(tmpName, dst); err != nil {\n\t\treturn fmt.Errorf(\"rename temp to %s: %w\", dst, err)\n\t}\n\treturn nil\n}\n","sourceCodeStart":909,"sourceCodeEnd":937,"githubUrl":"https://github.com/multica-ai/multica/blob/2c0912b6ec764b373d44eeea1e80f0d9f11ab417/server/internal/daemon/execenv/hermes_home.go#L909-L937","documentation":"writeFileAtomic could not Chmod the temp file to the requested mode (0600 for configs that may hold inline secrets). The data is already written; only tightening permissions failed. On some filesystems chmod is unsupported or partially emulated, and the helper refuses to publish a file with looser permissions than intended.","triggerScenarios":"Destination on FAT/exFAT or a network filesystem (CIFS/SMB without POSIX extensions, some NFS configs) where chmod returns EPERM/EINVAL; Windows ACL semantics making Go's Chmod fail; overlayfs edge cases in containers.","commonSituations":"Env RootDir placed on a Windows share, USB/exFAT drive, or container volume with restricted syscall support; secrets-bearing config written through this path fails closed rather than shipping world-readable.","solutions":["Move the env RootDir (and Hermes homes) to a POSIX-permission filesystem (ext4, xfs, apfs, NTFS via Go's ACL mapping usually works).","For CIFS mounts, mount with the `noperm`/posix options or relocate the directory.","If the volume type is fixed and cannot honor 0600, accept that derived configs cannot be written there and use a different location.","Retry after remounting with permission support."],"exampleFix":null,"handlingStrategy":"validation","validationCode":"probe, err := os.CreateTemp(dir, \".perm-probe-*\")\nif err != nil { return err }\ndefer os.Remove(probe.Name())\nprobe.Close()\nif err := os.Chmod(probe.Name(), 0o600); err != nil {\n\treturn fmt.Errorf(\"filesystem at %s cannot honor chmod — pick another location\", dir)\n}","typeGuard":null,"tryCatchPattern":"if err := writeFileAtomic(dst, data, perm); err != nil {\n\tvar pe *os.PathError\n\tif errors.As(err, &pe) && strings.Contains(err.Error(), \"chmod temp\") &&\n\t\t(errors.Is(pe.Err, syscall.EPERM) || errors.Is(pe.Err, syscall.ENOTSUP)) {\n\t\tlog.Printf(\"%s does not support permission bits; relocate env root\", filepath.Dir(dst))\n\t}\n\treturn err\n}","preventionTips":["Do not place env roots on FAT/exFAC or permission-less network mounts.","Smoke-test the chmod path at daemon start on any new volume type."],"tags":["filesystem","permissions","atomic-write","cross-platform","hermes"],"backgroundTag":null,"analyzedSha":"2c0912b6ec764b373d44eeea1e80f0d9f11ab417","analyzedAt":"2026-08-15T13:25:18.241Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}