make docker-test failed with stack trace

I observed non-repeating test failure when running make docker-test with the following stack trace:

time="2024-05-21T14:52:52Z" level=error msg="found appropriate key" end_at="2024-05-21 14:52:53.511537 +0000 +0000" i=0 key="MCe0rrUhsJzzVVbofkCxGEIlJwpO/0RyhDCLq2yioHU=" now="2024-05-21 14:52:52.84825605 +0000 UTC m=+22.457378130" start_at="2024-05-21 14:52:52.511537 +0000 +0000"
{"level":"info","service":"cbp-request-logs","httpRequest":{"proto":"HTTP/1.1","remoteIP":"127.0.0.1:58572","requestID":"62b20045bd58/dwjXbcnzyu-000039","requestMethod":"POST","requestPath":"/v3/blindedToken/grKnNUDuXE/redemption/","requestURL":"http://127.0.0.1:35625/v3/blindedToken/grKnNUDuXE/redemption/"},"httpResponse":{"bytes":13,"elapsed":113.702048,"header":{"content-type":"application/json"},"status":200},"timestamp":"2024-05-21T14:52:52.959216825Z","message":"Response: 200 OK"}
    suite.go:87: test panicked: runtime error: invalid memory address or nil pointer dereference
        goroutine 353 [running]:
        runtime/debug.Stack()
                /usr/local/go/src/runtime/debug/stack.go:24 +0x65
        github.com/stretchr/testify/suite.failOnPanic(0xc000725a00, {0xdac880, 0x1726430})
                /go/pkg/mod/github.com/stretchr/testify@v1.8.4/suite/suite.go:87 +0x3b
        github.com/stretchr/testify/suite.Run.func1.1()
                /go/pkg/mod/github.com/stretchr/testify@v1.8.4/suite/suite.go:183 +0x252
        panic({0xdac880, 0x1726430})
                /usr/local/go/src/runtime/panic.go:838 +0x207
        github.com/brave-intl/challenge-bypass-ristretto-ffi.(*UnblindedToken).DeriveVerificationKey.func1(0x51ad07?)
                /go/pkg/mod/github.com/brave-intl/challenge-bypass-ristretto-ffi@v0.0.0-20220418231828-419995e4a873/lib.go:341 +0x14
        github.com/brave-intl/challenge-bypass-ristretto-ffi.(*UnblindedToken).DeriveVerificationKey(0x1199040?)
                /go/pkg/mod/github.com/brave-intl/challenge-bypass-ristretto-ffi@v0.0.0-20220418231828-419995e4a873/lib.go:341 +0x57
        github.com/brave-intl/challenge-bypass-server/server.(*ServerTestSuite).prepareRedemption(0xc0004545b0, 0xedddeac3c?, {0xea26ee, 0xc})
                /src/server/server_test.go:541 +0x4e
        github.com/brave-intl/challenge-bypass-server/server.(*ServerTestSuite).TestRedeemV3(0xc0004545b0)
                /src/server/server_test.go:680 +0xa4d
        reflect.Value.call({0xc00064c720?, 0xc000532bf0?, 0x0?}, {0xe9b9bc, 0x4}, {0xc000517e70, 0x1, 0xc000517d80?})
                /usr/local/go/src/reflect/value.go:556 +0x845
        reflect.Value.Call({0xc00064c720?, 0xc000532bf0?, 0xc0004545b0?}, {0xc000517e70, 0x1, 0x1})
                /usr/local/go/src/reflect/value.go:339 +0xbf
        github.com/stretchr/testify/suite.Run.func1(0xc000725a00)
                /go/pkg/mod/github.com/stretchr/testify@v1.8.4/suite/suite.go:197 +0x4b6
        testing.tRunner(0xc000725a00, 0xc0003dfb90)
                /usr/local/go/src/testing/testing.go:1439 +0x102
        created by testing.(*T).Run
                /usr/local/go/src/testing/testing.go:1486 +0x35f
...
=== RUN   TestServerTestSuite/TestRunRotate
--- FAIL: TestServerTestSuite (27.56s)
    --- PASS: TestServerTestSuite/TestCreateIssuerV3 (0.02s)
    --- PASS: TestServerTestSuite/TestDeleteIssuerKeysV3 (2.01s)
    --- PASS: TestServerTestSuite/TestGetIssuerV2 (0.01s)
    --- PASS: TestServerTestSuite/TestIssueRedeem (0.01s)
    --- PASS: TestServerTestSuite/TestIssueRedeemV2 (0.32s)
    --- PASS: TestServerTestSuite/TestIssuerGetAll (0.01s)
    --- PASS: TestServerTestSuite/TestNewIssueRedeemV2 (0.23s)
    --- PASS: TestServerTestSuite/TestPing (0.00s)
    --- FAIL: TestServerTestSuite/TestRedeemV3 (10.46s)
    --- PASS: TestServerTestSuite/TestRotateTimeAwareIssuer (4.03s)
    --- PASS: TestServerTestSuite/TestRunRotate (0.01s)

This stack trace was only observed once.

I got another test failure in TestServerTestSuite/TestRedeemV3:

{"level":"warn","service":"cbp-request-logs","httpRequest":{"proto":"HTTP/1.1","remoteIP":"127.0.0.1:36730","requestID":"17596d250a4f/xPXNCMNnvA-000037","requestMethod":"POST","requestPath":"/v3/blindedToken/Y5TSCyNk62/redemption/","requestURL":"http://127.0.0.1:36093/v3/blindedToken/Y5TSCyNk62/redemption/"},"httpResponse":{"body":"{\"message\":\"Could not verify that token redemption is valid\",\"code\":400}\n","bytes":73,"elapsed":3.281374,"header":{"content-type":"application/json"},"status":400},"timestamp":"2024-05-21T16:29:54.70376076Z","message":"Response: 400 Client Error"}
    server_test.go:688:
                Error Trace:    /src/server/server_test.go:688
                Error:          Not equal:
                                expected: 200
                                actual  : 400
                Test:           TestServerTestSuite/TestRedeemV3
=== RUN   TestServerTestSuite/TestRotateTimeAwareIssuer
<nil>
=== RUN   TestServerTestSuite/TestRunRotate
--- FAIL: TestServerTestSuite (25.57s)
    --- PASS: TestServerTestSuite/TestCreateIssuerV3 (0.02s)
    --- PASS: TestServerTestSuite/TestDeleteIssuerKeysV3 (2.02s)
    --- PASS: TestServerTestSuite/TestGetIssuerV2 (0.01s)
    --- PASS: TestServerTestSuite/TestIssueRedeem (0.02s)
    --- PASS: TestServerTestSuite/TestIssueRedeemV2 (1.06s)
    --- PASS: TestServerTestSuite/TestIssuerGetAll (0.01s)
    --- PASS: TestServerTestSuite/TestNewIssueRedeemV2 (0.46s)
    --- PASS: TestServerTestSuite/TestPing (0.00s)
    --- FAIL: TestServerTestSuite/TestRedeemV3 (7.00s)
    --- PASS: TestServerTestSuite/TestRotateTimeAwareIssuer (4.03s)
    --- PASS: TestServerTestSuite/TestRunRotate (0.01s)
FAIL
FAIL    github.com/brave-intl/challenge-bypass-server/server    25.593s

brave-intl / challenge-bypass-server

make docker-test failed with stack trace #709