fix(envd): fall back to lazy unmount when forced NFS umount fails

[ValentaTomas]

Falls back to umount --lazy when forced unmount on resume fails with EBUSY (customer FDs hold the mount).

[cursor]

PR Summary

Medium Risk
Touches NFS unmount behavior during volume lifecycle changes; incorrect timeout/behavior could leave mounts stuck or mask real failures, impacting resume reliability.

Overview
When umount --force fails for stale NFS mounts, unmountNFS now logs a warning and retries with umount --lazy using a fresh 2s timeout context instead of failing immediately. The envd version is bumped to 0.5.24.

^{Reviewed by Cursor Bugbot for commit ff2c941. Bugbot is set up for automated code reviews on this repo. Configure here.}

[codecov]

❌ 7 Tests Failed:

Tests completed	Failed	Passed	Skipped
2620	7	2613	7

View the full list of 13 ❄️ flaky test(s)

github.com/e2b-dev/infra/tests/integration/internal/tests/api/metrics::TestTeamMetrics

Flake rate in main: 71.70% (Passed 221 times, Failed 560 times)

Stack Traces | 1.32s run time

=== RUN   TestTeamMetrics
=== PAUSE TestTeamMetrics
=== CONT  TestTeamMetrics
    team_metrics_test.go:61: 
        	Error Trace:	.../api/metrics/team_metrics_test.go:61
        	Error:      	Should be true
        	Test:       	TestTeamMetrics
        	Messages:   	MaxConcurrentSandboxes should be >= 0
--- FAIL: TestTeamMetrics (1.32s)

github.com/e2b-dev/infra/tests/integration/internal/tests/api/sandboxes::TestUpdateNetworkConfig

Flake rate in main: 76.85% (Passed 231 times, Failed 767 times)

Stack Traces | 34.1s run time

=== RUN   TestUpdateNetworkConfig
=== PAUSE TestUpdateNetworkConfig
=== CONT  TestUpdateNetworkConfig
--- FAIL: TestUpdateNetworkConfig (34.08s)

github.com/e2b-dev/infra/tests/integration/internal/tests/api/sandboxes::TestUpdateNetworkConfig/pause_resume_preserves_allow_internet_access_false

Flake rate in main: 77.39% (Passed 222 times, Failed 760 times)

Stack Traces | 2.09s run time

=== RUN   TestUpdateNetworkConfig/pause_resume_preserves_allow_internet_access_false
Executing command curl in sandbox i272pkskdy98vwhxyu6be
    sandbox_network_update_test.go:372: Command [curl] output: event:{start:{pid:1358}}
    sandbox_network_update_test.go:372: Command [curl] output: event:{end:{exit_code:35 exited:true status:"exit status 35" error:"exit status 35"}}
Executing command curl in sandbox i272pkskdy98vwhxyu6be
    sandbox_network_update_test.go:372: Command [curl] output: event:{start:{pid:1359}}
    sandbox_network_update_test.go:372: Command [curl] output: event:{end:{exit_code:35 exited:true status:"exit status 35" error:"exit status 35"}}
    sandbox_network_update_test.go:391: Command [curl] output: event:{start:{pid:1361}}
    sandbox_network_update_test.go:391: Command [curl] output: event:{data:{stdout:"HTTP/2 302 \r\nx-content-type-options: nosniff\r\nlocation: https://dns.google/\r\ndate: Sun, 17 May 2026 23:49:45 GMT\r\ncontent-type: text/html; charset=UTF-8\r\nserver: HTTP server (unknown)\r\ncontent-length: 216\r\nx-xss-protection: 0\r\nx-frame-options: SAMEORIGIN\r\nalt-svc: h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000\r\n\r\n"}}
    sandbox_network_update_test.go:391: Command [curl] output: event:{end:{exited:true status:"exit status 0"}}
    sandbox_network_update_test.go:391: Command [curl] completed successfully in sandbox i272pkskdy98vwhxyu6be
    sandbox_network_update_test.go:391: 
        	Error Trace:	.../api/sandboxes/sandbox_network_out_test.go:74
        	            				.../api/sandboxes/sandbox_network_update_test.go:60
        	            				.../api/sandboxes/sandbox_network_update_test.go:391
        	Error:      	An error is expected but got nil.
        	Test:       	TestUpdateNetworkConfig/pause_resume_preserves_allow_internet_access_false
        	Messages:   	https://8.8.8.8 should be blocked
--- FAIL: TestUpdateNetworkConfig/pause_resume_preserves_allow_internet_access_false (2.09s)

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestBindLocalhost

Flake rate in main: 56.36% (Passed 391 times, Failed 505 times)

Stack Traces | 0s run time

=== RUN   TestBindLocalhost
=== PAUSE TestBindLocalhost
=== CONT  TestBindLocalhost
--- FAIL: TestBindLocalhost (0.00s)

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestBindLocalhost/bind_localhost

Flake rate in main: 64.33% (Passed 219 times, Failed 395 times)

Stack Traces | 8s run time

=== RUN   TestBindLocalhost/bind_localhost
=== PAUSE TestBindLocalhost/bind_localhost
=== CONT  TestBindLocalhost/bind_localhost
Executing command python in sandbox iw7cmxswzvb730adop5j2
    localhost_bind_test.go:69: Command [python] output: event:{start:{pid:1278}}
Executing command python in sandbox if11ux28qndy0vz0x7kg8
    localhost_bind_test.go:90: 
        	Error Trace:	.../tests/envd/localhost_bind_test.go:90
        	Error:      	Not equal: 
        	            	expected: 200
        	            	actual  : 502
        	Test:       	TestBindLocalhost/bind_localhost
        	Messages:   	Unexpected status code 502 for bind address localhost
--- FAIL: TestBindLocalhost/bind_localhost (8.00s)

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestListDir

Flake rate in main: 53.85% (Passed 276 times, Failed 322 times)

Stack Traces | 1.24s run time

=== RUN   TestListDir
=== PAUSE TestListDir
=== CONT  TestListDir
--- FAIL: TestListDir (1.24s)
Executing command python in sandbox i863r8biwwhrh1ldhelqc

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestListDir/depth_0_lists_only_root_directory

Flake rate in main: 57.88% (Passed 219 times, Failed 301 times)

Stack Traces | 0.02s run time

=== RUN   TestListDir/depth_0_lists_only_root_directory
=== PAUSE TestListDir/depth_0_lists_only_root_directory
=== CONT  TestListDir/depth_0_lists_only_root_directory
    filesystem_test.go:97: 
        	Error Trace:	.../tests/envd/filesystem_test.go:97
        	Error:      	Received unexpected error:
        	            	unavailable: 502 Bad Gateway
        	Test:       	TestListDir/depth_0_lists_only_root_directory
--- FAIL: TestListDir/depth_0_lists_only_root_directory (0.02s)

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestListDir/depth_1_lists_root_directory

Flake rate in main: 57.88% (Passed 219 times, Failed 301 times)

Stack Traces | 0.01s run time

=== RUN   TestListDir/depth_1_lists_root_directory
=== PAUSE TestListDir/depth_1_lists_root_directory
=== CONT  TestListDir/depth_1_lists_root_directory
    filesystem_test.go:97: 
        	Error Trace:	.../tests/envd/filesystem_test.go:97
        	Error:      	Received unexpected error:
        	            	unavailable: 502 Bad Gateway
        	Test:       	TestListDir/depth_1_lists_root_directory
--- FAIL: TestListDir/depth_1_lists_root_directory (0.01s)

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestListDir/depth_2_lists_first_level_of_subdirectories_(in_this_case_the_root_directory)

Flake rate in main: 57.88% (Passed 219 times, Failed 301 times)

Stack Traces | 0.01s run time

=== RUN   TestListDir/depth_2_lists_first_level_of_subdirectories_(in_this_case_the_root_directory)
=== PAUSE TestListDir/depth_2_lists_first_level_of_subdirectories_(in_this_case_the_root_directory)
=== CONT  TestListDir/depth_2_lists_first_level_of_subdirectories_(in_this_case_the_root_directory)
    filesystem_test.go:97: 
        	Error Trace:	.../tests/envd/filesystem_test.go:97
        	Error:      	Received unexpected error:
        	            	unavailable: 502 Bad Gateway
        	Test:       	TestListDir/depth_2_lists_first_level_of_subdirectories_(in_this_case_the_root_directory)
--- FAIL: TestListDir/depth_2_lists_first_level_of_subdirectories_(in_this_case_the_root_directory) (0.01s)

github.com/e2b-dev/infra/tests/integration/internal/tests/envd::TestListDir/depth_3_lists_all_directories_and_files

Flake rate in main: 57.88% (Passed 219 times, Failed 301 times)

Stack Traces | 0.01s run time

=== RUN   TestListDir/depth_3_lists_all_directories_and_files
=== PAUSE TestListDir/depth_3_lists_all_directories_and_files
=== CONT  TestListDir/depth_3_lists_all_directories_and_files
    filesystem_test.go:97: 
        	Error Trace:	.../tests/envd/filesystem_test.go:97
        	Error:      	Received unexpected error:
        	            	unavailable: 502 Bad Gateway
        	Test:       	TestListDir/depth_3_lists_all_directories_and_files
--- FAIL: TestListDir/depth_3_lists_all_directories_and_files (0.01s)

github.com/e2b-dev/infra/tests/integration/internal/tests/orchestrator::TestSandboxMemoryIntegrity

Flake rate in main: 66.17% (Passed 229 times, Failed 448 times)

Stack Traces | 76.8s run time

=== RUN   TestSandboxMemoryIntegrity
=== PAUSE TestSandboxMemoryIntegrity
=== CONT  TestSandboxMemoryIntegrity
    sandbox_memory_integrity_test.go:26: Build completed successfully
--- FAIL: TestSandboxMemoryIntegrity (76.84s)

github.com/e2b-dev/infra/tests/integration/internal/tests/orchestrator::TestSandboxMemoryIntegrity/tmpfs_hash

Flake rate in main: 66.87% (Passed 219 times, Failed 442 times)

Stack Traces | 47.5s run time

=== RUN   TestSandboxMemoryIntegrity/tmpfs_hash
=== PAUSE TestSandboxMemoryIntegrity/tmpfs_hash
=== CONT  TestSandboxMemoryIntegrity/tmpfs_hash
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{start:{pid:1257}}
Executing command bash in sandbox ie9n13beuut9k8q2x7yju (user: root)
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stdout:"Total memory: 985 MB\nUsed memory before tmpfs mount: 186 MB\nFree memory before tmpfs mount: 798 MB\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stdout:"Memory to use in integrity test (80% of free, min 64MB): 638 MB\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"638+0 records in\n638+0 records out\n668991488 bytes (669 MB, 638 MiB) copied, 18.2238 s, 36.7 MB/s\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stderr:"\tCommand being timed: \"dd if=/dev/urandom of=/mnt/testfile bs=1M count=638\"\n\tUser time (seconds): 0.00\n\tSystem time (seconds): 17.92\n\tPercent of CPU this job got: 97%\n\tElapsed (wall clock) time (h:mm:ss or m:ss): 0:18.29\n\tAverage shared text size (kbytes): 0\n\tAverage unshared data size (kbytes): 0\n\tAverage stack size (kbytes): 0\n\tAverage total size (kbytes): 0\n\tMaximum resident set size (kbytes): 2628\n\tAverage resident set size (kbytes): 0\n\tMajor (requiring I/O) page faults: 3\n\tMinor (reclaiming a frame) page faults: 341\n\tVoluntary context switches: 4\n\tInvoluntary context switches: 162\n\tSwaps: 0\n\tFile system inputs: 176\n\tFile system outputs: 0\n\tSocket messages sent: 0\n\tSocket messages received: 0\n\tSignals delivered: 0\n\tPage size (bytes): 4096\n\tExit status: 0\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{data:{stdout:"Used memory after tmpfs mount and file fill: 831 MB\n"}}
    sandbox_memory_integrity_test.go:70: Command [bash] output: event:{end:{exited:true status:"exit status 0"}}
    sandbox_memory_integrity_test.go:70: Command [bash] completed successfully in sandbox i3ow5paenahyx425iu3th
Executing command bash in sandbox i3ow5paenahyx425iu3th (user: root)
    sandbox_memory_integrity_test.go:74: Command [bash] output: event:{start:{pid:1273}}
    sandbox_memory_integrity_test.go:74: Command [bash] output: event:{data:{stdout:"502d94d296998ee0fd5bb74e44341d6308ebdbd45bd2d152fb9a2f3901212b7e\n"}}
    sandbox_memory_integrity_test.go:74: Command [bash] output: event:{end:{exited:true status:"exit status 0"}}
    sandbox_memory_integrity_test.go:74: Command [bash] completed successfully in sandbox i3ow5paenahyx425iu3th
Executing command bash in sandbox i3ow5paenahyx425iu3th (user: root)
    sandbox_memory_integrity_test.go:99: Command [bash] output: event:{start:{pid:1276}}
    sandbox_memory_integrity_test.go:100: 
        	Error Trace:	.../tests/orchestrator/sandbox_memory_integrity_test.go:100
        	Error:      	Received unexpected error:
        	            	failed to execute command bash in sandbox i3ow5paenahyx425iu3th: invalid_argument: protocol error: incomplete envelope: unexpected EOF
        	Test:       	TestSandboxMemoryIntegrity/tmpfs_hash
--- FAIL: TestSandboxMemoryIntegrity/tmpfs_hash (47.48s)

github.com/e2b-dev/infra/tests/integration/internal/tests/proxies::TestSandboxAutoResumeViaProxy

Flake rate in main: 55.40% (Passed 223 times, Failed 277 times)

Stack Traces | 20.3s run time

=== RUN   TestSandboxAutoResumeViaProxy
=== PAUSE TestSandboxAutoResumeViaProxy
=== CONT  TestSandboxAutoResumeViaProxy
    auto_resume_test.go:97: [Status code: 502] Response body: {"sandboxId":"irxxx1ngw6vbsuvbtstat","message":"The sandbox is running but port is not open","port":8000,"code":502}
    auto_resume_test.go:97: [Status code: 502] Response body: {"sandboxId":"irxxx1ngw6vbsuvbtstat","message":"The sandbox is running but port is not open","port":8000,"code":502}
    auto_resume_test.go:97: [Status code: 502] Response body: {"sandboxId":"irxxx1ngw6vbsuvbtstat","message":"The sandbox is running but port is not open","port":8000,"code":502}
    auto_resume_test.go:116: 
        	Error Trace:	.../tests/proxies/auto_resume_test.go:116
        	Error:      	Received unexpected error:
        	            	Get "http://localhost:3002": context deadline exceeded (Client.Timeout exceeded while awaiting headers)
        	Test:       	TestSandboxAutoResumeViaProxy
--- FAIL: TestSandboxAutoResumeViaProxy (20.28s)

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[gemini-code-assist]

Code Review

The fallback to umount --lazy will not execute if the initial umount --force fails due to a context timeout because both commands share the same context. To ensure the mount is detached when the first command hangs, the fallback should be attempted with a fresh context or a separate timeout.

[ValentaTomas]

Superseded by #2700 (move envd into a dedicated network namespace), which addresses the root cause.

[claude]

LGTM, small defensive fallback for NFS unmount with the gemini-suggested fresh context fix already applied.

Extended reasoning...

Overview

Small two-file change in packages/envd: unmountNFS now falls back to umount --lazy when umount --force fails (customer FDs holding the mount), and the envd version is bumped to 0.5.24. Total logic change is ~7 lines.

Security risks

None. This is an internal-to-envd unmount fallback running on resume. No new inputs, no privilege changes, no exposure surface.

Level of scrutiny

Low. The change is mechanical, self-contained, and only adds a fallback on an existing error path. The prior failure mode was a hard error; the new behavior tries one more thing before returning the same error. The fresh-context concern raised by gemini-code-assist was already addressed (commit 36f8f9d) using context.WithoutCancel with a 2s timeout, so the lazy attempt isn't starved by the parent budget.

Other factors

Bug hunting system found no bugs. Codecov failures are all pre-existing flakes (>50% flake rate in main). No outstanding reviewer comments. Author noted this is bifrost-track and will be superseded by #2700, but the fix is still useful in the interim.