Lambda v2 runtime error

[johnmorrell]

I appreciate this is pre release, but when attempting to deploy the sample in the readme I am getting an unusual runtime error:

generic witness table at 0x56491ea2928c contains out-of-bounds requirement descriptor 0x13

The API Gateway v2 and lambda look to be correctly deployed and I am able see runtime logs up to runService()

Lambda was packaged using:

https://github.com/swift-server/swift-aws-lambda-runtime/releases

[adam-fowler]

Hmmm that's not a very helpful error message. Sounds like something bad went with the building. Are you using the archive command plugin?

I'm going to release a build that takes advantage of the new v2 beta runtime in the next week or so. If you could rebuild using the main branch and see if you still get the same error.

Check out the README to see how creating a lambda has changed.

[johnmorrell]

Thanks @adam-fowler, yes I am using main branch or hummingbird-lamba and 2.0.0-beta.1 release of swift-aws-lambda-runtime and using the following command to package within GitHub action:

swift package archive --allow-network-connections docker

[adam-fowler]

@sebsto have you seen this error before?

[sebsto]

Hello @johnmorrell
I never saw that error.
Can you share details about your build and deployment procedure ?
Where does the error message coming from ? (Is it something you read in CloudWatch logs)
Can you set the environment variable LOG_LEVEL=trace and share the full log ?
Can you invoke the Lambda function from the AWS Console (by passing a test APIGateway request) and check if this works ?

[johnmorrell]

Thanks @adam-fowler + @sebsto

Build procedure is one we have been using for v1 without issue:

• GitHub action running on ubuntu-latest
• Runs swift package archive --allow-network-connections docker
• Attach as asset to GitHub release

Then deployed with:

• GitHub action running on ubuntu-latest
• Downloads asset from GitHub release
• Runs SAM deploy (updated to use API Gateway v2)

main.swift

import HummingbirdLambda
import AWSLambdaEvents
import Logging

typealias AppRequestContext = BasicLambdaRequestContext<APIGatewayV2Request>
let logger = Logger(label: "hummingbird-lambda")
let router = Router(context: AppRequestContext.self)
router.get("hello") { _, _ in
    return "Hello"
}
let lambda = APIGatewayV2LambdaFunction(router: router)
logger.log(level: .info, "About to run service..")
try await lambda.runService()

The output from the lambda test Shows the log message from the application before failing:

[johnmorrell]

Using the same project/deploy I was able to run the Lambda example from the swift-aws-lambda-runtime release notes ok:

[sebsto]

Thank you John. This rules out some fundamental issue that would cause all Swift Lambda functions to crash.

I successfully deployed your code and invoked the function.
Here is my project. I let you inspect to find the differences with yours.

Package.swift

// swift-tools-version: 6.1
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "test",
    platforms: [.macOS(.v15)],
    dependencies: [
        .package(
            url: "https://github.com/swift-server/swift-aws-lambda-runtime", from: "2.0.0-beta.1"),
        .package(
            url: "https://github.com/hummingbird-project/hummingbird-lambda", branch: "main"),
        .package(url: "https://github.com/swift-server/swift-aws-lambda-events", from: "1.1.0"),
    ],
    targets: [
        .executableTarget(
            name: "test",
            dependencies: [
                .product(name: "HummingbirdLambda", package: "hummingbird-lambda"),
                .product(name: "AWSLambdaEvents", package: "swift-aws-lambda-events"),
            ]
        )
    ]
)

main.swift

import AWSLambdaEvents
import HummingbirdLambda
import Logging

typealias AppRequestContext = BasicLambdaRequestContext<APIGatewayV2Request>
let logger = Logger(label: "hummingbird-lambda")
let router = Router(context: AppRequestContext.self)
router.get("hello") { _, _ in
    return "Hello"
}
let lambda = APIGatewayV2LambdaFunction(router: router)
logger.info("About to run service..")
try await lambda.runService()

template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: SAM Template for APIGateway Lambda Example

Resources:
  # Lambda function
  APIGatewayLambda:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: .build/plugins/AWSLambdaPackager/outputs/AWSLambdaPackager/test/test.zip
      Timeout: 60
      Handler: swift.bootstrap  # ignored by the Swift runtime
      Runtime: provided.al2
      MemorySize: 512
      Architectures:
        - arm64
      Environment:
        Variables:
          # by default, AWS Lambda runtime produces no log
          # use `LOG_LEVEL: debug` for for lifecycle and event handling information
          # use `LOG_LEVEL: trace` for detailed input event information
          LOG_LEVEL: trace
      Events:
        HttpApiEvent:
          Type: HttpApi

Outputs:
  # print API Gateway endpoint
  APIGatewayEndpoint:
    Description: API Gateway endpoint URI"
    Value: !Sub "https://${ServerlessHttpApi}.execute-api.${AWS::Region}.amazonaws.com"

Build output

➜  swift package archive --allow-network-connections docker
-------------------------------------------------------------------------
building "test" in docker
-------------------------------------------------------------------------
updating "swift:amazonlinux2" docker image
  amazonlinux2: Pulling from library/swift
  5d0d7075c896: 
  Pulling fs layer
da4fd60e9b2b: Pulling fs layer
147460426330: Pulling fs layer
90a67f6797e4: Pulling fs layer
  5d0d7075c896: 
  Download complete
  147460426330: Download complete
  147460426330: Pull complete
  da4fd60e9b2b: 
  Download complete
  da4fd60e9b2b: Pull complete
  90a67f6797e4: 
  Download complete
  5d0d7075c896: Pull complete
  90a67f6797e4: Pull complete
  Digest: sha256:272083acfe92ee495c175c5aa0209b82806a8b278d5b68ee191523f9a3014521
Status: Downloaded newer image for swift:amazonlinux2
  docker.io/library/swift:amazonlinux2
building "test"
  Building for production...
  [0/54] Write sources
  [21/54] Compiling CNIOWindows shim.c
  [22/54] Compiling CNIODarwin shim.c
[24/54] Write sources
  [37/54] Compiling _AtomicsShims.c
[37/54] Write sources
  [41/54] Compiling CNIOWASI CNIOWASI.c
  [42/54] Compiling CNIOWindows WSAStartup.c
  [43/54] Compiling CNIOLinux liburing_shims.c
  [44/54] Compiling CNIOPosix event_loop_id.c
  [45/54] Compiling CNIOLinux shim.c
  [46/54] Compiling CNIOLLHTTP c_nio_http.c
  [47/54] Compiling CNIOLLHTTP c_nio_api.c
  [48/54] Write swift-version-24593BA9C3E375BF.txt
  [49/64] Compiling c-nioatomics.c
  [51/64] Compiling ServiceContextModule ServiceContext.swift
  [51/64] Compiling c-atomics.c
  [53/64] Compiling _NIOBase64 Base64.swift
  [53/64] Compiling CNIOLLHTTP c_nio_llhttp.c
  [55/66] Compiling Instrumentation Instrument.swift
  [56/66] Compiling InternalCollectionsUtilities FixedWidthInteger+roundUpToPowerOfTwo.swift
  [57/66] Compiling ConcurrencyHelpers Lock.swift
  [58/70] Compiling _NIODataStructures Heap.swift
  [59/74] Compiling CoreMetrics Locks.swift
  [60/74] Compiling HeapModule Heap+Descriptions.swift
[61/74] Compiling NIOConcurrencyHelpers NIOAtomic.swift
  [62/75] Compiling UnixSignals UnixSignal.swift
  [63/75] Compiling Logging Locks.swift
  [64/75] Compiling DequeModule Deque+Codable.swift
  [65/75] Compiling Tracing InstrumentationSystem+Tracing.swift
  [66/75] Compiling Atomics OptionalRawRepresentable.swift
  [67/76] Compiling Metrics Metrics.swift
  [68/76] Compiling HTTPTypes HTTPField.swift
  [69/77] Compiling ExtrasBase64 Base32.swift
  [70/77] Compiling OrderedCollections _HashTable+Bucket.swift
  [71/78] Compiling BitCollections BitArray+BitwiseOperations.swift
  [72/78] Compiling HashTreeCollections _AncestorHashSlots.swift
  [73/78] Compiling AsyncAlgorithms AsyncAdjacentPairsSequence.swift
  [74/79] Compiling _RopeModule BigString+Builder.swift
  [75/80] Compiling Collections Collections.swift
  [76/80] Compiling ServiceLifecycle AsyncCancelOnGracefulShutdownSequence.swift
  [77/80] Compiling NIOCore AddressedEnvelope.swift
  [78/83] Compiling NIOHTTPTypes NIOHTTPTypes.swift
  [79/83] Compiling AWSLambdaEvents ALB.swift
  [80/83] Compiling NIOEmbedded AsyncTestingChannel.swift
  [81/83] Compiling NIOPosix BSDSocketAPICommon.swift
  [82/84] Compiling NIO Exports.swift
  [83/85] Compiling NIOHTTP1 ByteCollectionUtils.swift
  [84/88] Compiling NIOHTTPTypesHTTP1 HTTP1ToHTTPCodec.swift
  [85/88] Compiling NIOExtras DebugInboundEventsHandler.swift
  [86/89] Compiling AWSLambdaRuntime ControlPlaneRequest.swift
  [87/89] Compiling HummingbirdCore Deprecations.swift
  [88/90] Compiling Hummingbird Application.swift
  [89/91] Compiling HummingbirdLambda APIGatewayLambda.swift
  [90/92] Compiling test main.swift
  [90/92] Write Objects.LinkFileList
  /usr/lib/swift_static/linux/libFoundationEssentials.a(Data+Writing.swift.o):_ThreadLocal.swift.o:function $s20FoundationEssentials19createTemporaryFile33_FC9EC52B075D2ACCFF86F1C9F84293BELL2at6inPath6prefix7options7variants5Int32V_SStSS_AA0Q5OrURLOSSAA4DataV14WritingOptionsVSSSgtKFTf4nnndn_n: warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
/usr/lib/swift_static/linux/libFoundationEssentials.a(Data+Writing.swift.o):_ThreadLocal.swift.o:function $s20FoundationEssentials19createTemporaryFile33_FC9EC52B075D2ACCFF86F1C9F84293BELL2at6inPath6prefix7options7variants5Int32V_SStSS_AA0Q5OrURLOSSAA4DataV14WritingOptionsVSSSgtKFTf4nnndn_n: warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
/usr/lib/swift_static/linux/libFoundationEssentials.a(Data+Writing.swift.o):_ThreadLocal.swift.o:function $s20FoundationEssentials19createTemporaryFile33_FC9EC52B075D2ACCFF86F1C9F84293BELL2at6inPath6prefix7options7variants5Int32V_SStSS_AA0Q5OrURLOSSAA4DataV14WritingOptionsVSSSgtKFTf4nnndn_n: warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
/usr/lib/swift_static/linux/libFoundationEssentials.a(Data+Writing.swift.o):_ThreadLocal.swift.o:function $s20FoundationEssentials19createTemporaryFile33_FC9EC52B075D2ACCFF86F1C9F84293BELL2at6inPath6prefix7options7variants5Int32V_SStSS_AA0Q5OrURLOSSAA4DataV14WritingOptionsVSSSgtKFTf4nnndn_n: warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
/usr/lib/swift_static/linux/libFoundationEssentials.a(Data+Writing.swift.o):_ThreadLocal.swift.o:function $s20FoundationEssentials19createTemporaryFile33_FC9EC52B075D2ACCFF86F1C9F84293BELL2at6inPath6prefix7options7variants5Int32V_SStSS_AA0Q5OrURLOSSAA4DataV14WritingOptionsVSSSgtKFTf4nnndn_n: warning: the use of `mktemp' is dangerous, better use `mkstemp' or `mkdtemp'
[91/92] Linking test
  Build of product 'test' complete! (38.41s)
-------------------------------------------------------------------------
archiving "test"
-------------------------------------------------------------------------
1 archive created

Terminal output

➜  http https://w4m1t6i436.execute-api.eu-west-3.amazonaws.com/hello
HTTP/1.1 200 OK
Apigw-Requestid: Otx3Zi1TiGYEJvg=
Connection: keep-alive
Content-Length: 5
Content-Type: text/plain; charset=utf-8
Date: Sun, 03 Aug 2025 06:08:59 GMT

Hello

Lambda logs (trace level)

2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:55.901000 INIT_START Runtime Version: provided:al2.v119        Runtime Version ARN: arn:aws:lambda:eu-west-3::runtime:84c424dcd40a5f2f234165bd1169ef859c46d41e22eee69be9b8909fcd3051eb
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.033000 2025-08-03T06:08:56+0000 info hummingbird-lambda: [test] About to run service..
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.055000 2025-08-03T06:08:56+0000 debug Hummingbird: sl-cancellationSignals=[] sl-gracefulShutdownSignals=[SIGTERM, SIGINT] sl-services=[HummingbirdLambda.LambdaFunction<Hummingbird.RouterResponder<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>, AWSLambdaEvents.APIGatewayV2Request, AWSLambdaEvents.APIGatewayV2Response>(responder: Hummingbird.RouterResponder<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>(trie: Hummingbird.RouterTrie<Hummingbird.EndpointResponders<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>>, notFoundResponder: Hummingbird.NotFoundResponder<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>(), options: Hummingbird.RouterOptions(rawValue: 0)), services: [], logger: Logging.Logger(_storage: Logging.Logger.Storage), processesRunBeforeLambdaStart: [])] [ServiceLifecycle] Starting service lifecycle
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.060000 2025-08-03T06:08:56+0000 debug Hummingbird: sl-service=LambdaFunction<RouterResponder<BasicLambdaRequestContext<APIGatewayV2Request>>, APIGatewayV2Request, APIGatewayV2Response>(responder: Hummingbird.RouterResponder<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>(trie: Hummingbird.RouterTrie<Hummingbird.EndpointResponders<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>>, notFoundResponder: Hummingbird.NotFoundResponder<HummingbirdLambda.BasicLambdaRequestContext<AWSLambdaEvents.APIGatewayV2Request>>(), options: Hummingbird.RouterOptions(rawValue: 0)), services: [], logger: Logging.Logger(_storage: Logging.Logger.Storage), processesRunBeforeLambdaStart: []) [ServiceLifecycle] Starting service
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.073000 2025-08-03T06:08:56+0000 debug LambdaRuntime: [AWSLambdaRuntime] LambdaRuntime initialized
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.073000 2025-08-03T06:08:56+0000 debug Hummingbird: sl-cancellationSignals=[] sl-gracefulShutdownSignals=[] sl-services=[PreludeService<LambdaRuntimeService<LambdaCodableAdapter<LambdaHandlerAdapter<APIGatewayV2Request, APIGatewayV2Response, ClosureHandler<APIGatewayV2Request, APIGatewayV2Response>>, APIGatewayV2Request, APIGatewayV2Response, LambdaJSONEventDecoder, LambdaJSONOutputEncoder<APIGatewayV2Response>>>>] [ServiceLifecycle] Starting service lifecycle
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.073000 2025-08-03T06:08:56+0000 debug Hummingbird: sl-service=PreludeService<LambdaRuntimeService<LambdaCodableAdapter<LambdaHandlerAdapter<APIGatewayV2Request, APIGatewayV2Response, ClosureHandler<APIGatewayV2Request, APIGatewayV2Response>>, APIGatewayV2Request, APIGatewayV2Response, LambdaJSONEventDecoder, LambdaJSONOutputEncoder<APIGatewayV2Response>>>> [ServiceLifecycle] Starting service
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.079000 2025-08-03T06:08:56+0000 trace LambdaRuntime: lambda_ip=127.0.0.1 lambda_port=9001 [AWSLambdaRuntime] Connection to control plane created

First request on invalid URL :
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.081000 START RequestId: d453c2e9-4277-4749-b1bc-e90001d7d35b Version: $LATEST
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.081000 2025-08-03T06:08:56+0000 trace LambdaRuntime: Event's first bytes={"version":"2.0","routeKey":"$default","rawPath":"/","rawQueryString":"","headers":{"accept":"*/*","accept-encoding":"gzip, deflate","content-length":"0","host":"w4m1t6i436.execute-api.eu-west-3.amazonaws.com","user-agent":"HTTPie/3.2.4","x-amzn-trace-id":"Root=1-688efcf7-79145c81607e32f8233b7066","x-forwarded-for":"81.49.207.77","x-forwarded-port":"443","x-forwarded-proto":"https"},"requestContext":{"accountId":"401955065246","apiId":"w4m1t6i436","domainName":"w4m1t6i436.execute-api.eu-west-3.amazonaws.com","domainPrefix":"w4m1t6i436","http":{"method":"GET","path":"/","protocol":"HTTP/1.1","sourceIp":"81.49.207.77","userAgent":"HTTPie/3.2.4"},"requestId":"Otx2ugv2iGYEJsQ=","routeKey":"$default","stage":"$default","time":"03/Aug/2025:06:08:55 +0000","timeEpoch":1754201335480},"isBase64Encoded":false} aws-request-id=d453c2e9-4277-4749-b1bc-e90001d7d35b [AWSLambdaRuntime] Sending invocation event to lambda handler
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.091000 END RequestId: d453c2e9-4277-4749-b1bc-e90001d7d35b
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:56.091000 REPORT RequestId: d453c2e9-4277-4749-b1bc-e90001d7d35b       Duration: 10.32 ms      Billed Duration: 189 ms Memory Size: 512 MB     Max Memory Used: 43 MB       Init Duration: 178.49 ms

Second request on /hello
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:59.743000 START RequestId: 20acfffc-eeae-4776-8699-c6f4948d5a7c Version: $LATEST
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:59.743000 2025-08-03T06:08:59+0000 trace LambdaRuntime: Event's first bytes={"version":"2.0","routeKey":"$default","rawPath":"/hello","rawQueryString":"","headers":{"accept":"*/*","accept-encoding":"gzip, deflate","content-length":"0","host":"w4m1t6i436.execute-api.eu-west-3.amazonaws.com","user-agent":"HTTPie/3.2.4","x-amzn-trace-id":"Root=1-688efcfb-4910b1bc734c028f0af01746","x-forwarded-for":"81.49.207.77","x-forwarded-port":"443","x-forwarded-proto":"https"},"requestContext":{"accountId":"401955065246","apiId":"w4m1t6i436","domainName":"w4m1t6i436.execute-api.eu-west-3.amazonaws.com","domainPrefix":"w4m1t6i436","http":{"method":"GET","path":"/hello","protocol":"HTTP/1.1","sourceIp":"81.49.207.77","userAgent":"HTTPie/3.2.4"},"requestId":"Otx3Zi1TiGYEJvg=","routeKey":"$default","stage":"$default","time":"03/Aug/2025:06:08:59 +0000","timeEpoch":1754201339717},"isBase64Encoded":false} aws-request-id=20acfffc-eeae-4776-8699-c6f4948d5a7c [AWSLambdaRuntime] Sending invocation event to lambda handler
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:59.745000 END RequestId: 20acfffc-eeae-4776-8699-c6f4948d5a7c
2025/08/03/[$LATEST]3a743f611f554b6aa53a5accd910b20d 2025-08-03T06:08:59.745000 REPORT RequestId: 20acfffc-eeae-4776-8699-c6f4948d5a7c       Duration: 1.57 ms       Billed Duration: 2 ms   Memory Size: 512 MB     Max Memory Used: 44 MB

[sebsto]

The "Runtime.ExitError" error seems to indicate the binary file (bootstrap) crashes without generating any output or backtrace information.

generic witness table at 0x56491ea2928c contains out-of-bounds requirement descriptor 0x13

This error message indicates a Swift runtime issue related to protocol witness tables, which are Swift's mechanism for dynamic dispatch with protocols.

We can exclude an architecture mistmatch (arm64 vs x64) otherwise the binary would not load at all. Here, you receive some logging message, indicating the binary starts to execute normally.

Did you configure your Lambda runtime environment to use Amazon Linux 2 and not Amazon Linux 2023 ?

In your template.yaml file:

      Runtime: provided.al2

[johnmorrell]

Thanks @sebsto that's very helpful. I was able to deploy and run the example using the minimal Package.json file your provided.

I was working in an existing project with other dependencies and targets. It took a bit of trial and error to identify, but the thing that results in this error is the inclusion of postgres-nio. By inclusion I simply mean adding the dependency to the target, so you may see this error by updating the Package.json to:

// swift-tools-version: 6.1
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "test",
    platforms: [.macOS(.v15)],
    dependencies: [
        .package(url: "https://github.com/swift-server/swift-aws-lambda-runtime", from: "2.0.0-beta.1"),
        .package(url: "https://github.com/hummingbird-project/hummingbird-lambda", branch: "main"),
        .package(url: "https://github.com/swift-server/swift-aws-lambda-events", from: "1.1.0"),
        .package(url: "https://github.com/vapor/postgres-nio", exact: "1.26.2"),
    ],
    targets: [
        .executableTarget(
            name: "test",
            dependencies: [
                .product(name: "HummingbirdLambda", package: "hummingbird-lambda"),
                .product(name: "AWSLambdaEvents", package: "swift-aws-lambda-events"),
                .product(name: "PostgresNIO", package: "postgres-nio"),
            ]
        )
    ]
)

[sebsto]

Thank you for the follow up. I'll try to replicate on my minimal setup.
@gwynne is our PostgresNIO goddess. I will ask her if this rings a bell

[gwynne]

It does, in fact, but we've never been able to pin down the source of that particular error. I would have to defer in my turn to @fabianfett for further insight.

[sebsto]

I added the PostgresNIO dependency, as suggested, to my sample project and I cannot reproduce.

    dependencies: [
        .package(
            url: "https://github.com/swift-server/swift-aws-lambda-runtime.git",
            from: "2.0.0-beta.1"
        ),
        .package(
            url: "https://github.com/hummingbird-project/hummingbird-lambda.git",
            branch: "main"
        ),
        .package(url: "https://github.com/swift-server/swift-aws-lambda-events.git", from: "1.1.0"),
        .package(url: "https://github.com/vapor/postgres-nio", exact: "1.26.2"),
    ],
    targets: [
        .executableTarget(
            name: "HBLambda",
            dependencies: [
                .product(name: "HummingbirdLambda", package: "hummingbird-lambda"),
                .product(name: "AWSLambdaEvents", package: "swift-aws-lambda-events"),
                .product(name: "PostgresNIO", package: "postgres-nio"),
            ]
        )
    ]
)

bcd07458a91c :: swift/lambda/swift-aws-lambda-runtime ‹sebsto/hummingbird*› » http https://patl4y5sr5.execute-api.eu-west-3.amazonaws.com/hello                                                                    1 ↵
HTTP/1.1 200 OK
Apigw-Requestid: OyPI9jj4iGYEM1A=
Connection: keep-alive
Content-Length: 5
Content-Type: text/plain; charset=utf-8
Date: Mon, 04 Aug 2025 14:36:28 GMT

Hello

The full project is available from this PR
swift-server/swift-aws-lambda-runtime#544

[sebsto]

@johnmorrell did you entirely delete the .build directory before compiling this sample project ?

[sebsto]

@johnmorrell Are you building on GitHub on an Amazon Linux 2 image ? (not on the image provided by Docker, which is based on Ubuntu)

I use swift:6.1-amazonlinux2

The reason I asked is because Amazon Q told me:

"That usually comes from mixing Swift package dependencies that were built with different Swift compiler versions (or more specifically, different Swift ABI/runtime versions)."

This is the type of error that might happen if you compile the binary on Ubuntu and run it on Amazon Linux 2 (Lambda)

[gwynne]

@MahdiBM also encountered this issue a couple months ago while building penny-bot lambdas. I don't recall what he ended up doing about it, though.