x/tools/gopls: panic in MethodSets: nil data for package

[findleyr]

Just encountered this panic while using gopls@master:

panic: nil data for golang.org/x/tools/internal/gopathwalk [golang.org/x/tools/internal/gopathwalk.test]

goroutine 4697562 [running]:
golang.org/x/tools/gopls/internal/lsp/cache.(*snapshot).MethodSets(0xc016d36dc0?, {0x10f1328?, 0xc019dde270?}, {0xc0058f1000, 0x2da, 0x0?})
        /home/rfindley/src/tools2/gopls/internal/lsp/cache/snapshot.go:688 +0x2f4
golang.org/x/tools/gopls/internal/lsp/source.expandMethodSearch({0x10f1328?, 0xc019dde270}, {0x10fe550?, 0xc016d36dc0}, 0xc01b62f5c0, {0x10ed678?, 0xc03cb72410}, 0xc019dde450, 0xc019dde4b0)
        /home/rfindley/src/tools2/gopls/internal/lsp/source/references.go:392 +0x45a
golang.org/x/tools/gopls/internal/lsp/source.ordinaryReferences({0x10f1328?, 0xc019dde270}, {0x10fe550?, 0xc016d36dc0}, {0xc011ac8780?, 0xc0155bb740?}, {0x10?, 0x0?})
        /home/rfindley/src/tools2/gopls/internal/lsp/source/references.go:295 +0x74c
golang.org/x/tools/gopls/internal/lsp/source.references({0x10f12b8?, 0xc017e01540?}, {0x10fe550, 0xc016d36dc0}, {0x10f2180?, 0xc0155bb740?}, {0xa648f00?, 0xc0?}, 0x1)
        /home/rfindley/src/tools2/gopls/internal/lsp/source/references.go:76 +0x1ce
golang.org/x/tools/gopls/internal/lsp/source.References({0x10f12b8?, 0xc017e01540?}, {0x10fe550?, 0xc016d36dc0?}, {0x10f2180?, 0xc0155bb740?}, {0xcfe1c0?, 0x0?}, 0x40?)
        /home/rfindley/src/tools2/gopls/internal/lsp/source/references.go:40 +0x4f
golang.org/x/tools/gopls/internal/lsp.(*Server).references(0xcfe1c0?, {0x10f12b8, 0xc017e01540}, 0xc0189b2740)
        /home/rfindley/src/tools2/gopls/internal/lsp/references.go:24 +0x192
golang.org/x/tools/gopls/internal/lsp.(*Server).References(0xc0112fa160?, {0x10f12b8?, 0xc017e01540?}, 0xcfe1c0?)
        /home/rfindley/src/tools2/gopls/internal/lsp/server_gen.go:204 +0x1d
golang.org/x/tools/gopls/internal/lsp/protocol.serverDispatch({0x10f12b8, 0xc017e01540}, {0x1101e90, 0xc00791e000}, 0xc019dde0f0, {0x10f1558, 0xc0189b26c0})
        /home/rfindley/src/tools2/gopls/internal/lsp/protocol/tsserver.go:505 +0x243a
golang.org/x/tools/gopls/internal/lsp/protocol.ServerHandler.func1({0x10f12b8, 0xc017e01540}, 0xc019dde0f0, {0x10f1558, 0xc0189b26c0})
        /home/rfindley/src/tools2/gopls/internal/lsp/protocol/protocol.go:157 +0x8a
golang.org/x/tools/gopls/internal/lsp/lsprpc.handshaker.func1({0x10f12b8, 0xc017e01540}, 0xc019dde0f0, {0x10f1558?, 0xc0189b26c0?})
        /home/rfindley/src/tools2/gopls/internal/lsp/lsprpc/lsprpc.go:519 +0x9d5
golang.org/x/tools/internal/jsonrpc2.MustReplyHandler.func1({0x10f12b8, 0xc017e01540}, 0xc0013ad110, {0x10f1558?, 0xc0189b26c0?})
        /home/rfindley/src/tools2/internal/jsonrpc2/handler.go:35 +0xe5
golang.org/x/tools/internal/jsonrpc2.AsyncHandler.func1.2()
        /home/rfindley/src/tools2/internal/jsonrpc2/handler.go:103 +0x96
created by golang.org/x/tools/internal/jsonrpc2.AsyncHandler.func1 in goroutine 3287406
        /home/rfindley/src/tools2/internal/jsonrpc2/handler.go:100 +0x1ed
exit status 2

[findleyr]

CC @adonovan

[adonovan]

Failure to check the error result from the toplevel call to the recursive collectImportPromises?

[findleyr]

Duh, thanks for investigating.

Since this code has changed so much, let's close this issue.