### What version of Go are you using (`go version`)?
<pre>
$ gotip version
…go version devel go1.20-e09bbae Sat Oct 29 04:48:07 2022 +0000 linux/amd64
</pre>
Same result with 1.18.6, 1.19.
### Does this issue reproduce with the latest release?
Yes
### What operating system and processor architecture are you using (`go env`)?
<details><summary><code>go env</code> Output</summary><br><pre>
$ go env
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/icio/.cache/go-build"
GOENV="/home/icio/.config/go/env"
GOEXE=""
GOEXPERIMENT=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOINSECURE=""
GOMODCACHE="/home/icio/go/pkg/mod"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/icio/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/home/icio/sdk/go"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/home/icio/sdk/go/pkg/tool/linux_amd64"
GOVCS=""
GOVERSION="devel go1.20-e09bbae Sat Oct 29 04:48:07 2022 +0000"
GCCGO="gccgo"
GOAMD64="v1"
AR="ar"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD="/home/icio/go/src/github.com/icio/go-get-panic/go.mod"
GOWORK=""
CGO_CFLAGS="-O2 -g"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-O2 -g"
CGO_FFLAGS="-O2 -g"
CGO_LDFLAGS="-O2 -g"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -Wl,--no-gc-sections -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build2460736486=/tmp/go-build -gno-record-gcc-switches"
</pre></details>
### What did you do?
Run `go get -u golang.org/x/tools` with go.mod:
```go.mod
module github.com/icio/go-get-panic
go 1.18
require (
golang.org/x/net v0.1.0
golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f
golang.org/x/text v0.4.0
)
```
### What did you expect to see?
go.mod updated with latest golang.org/x/tools version.
### What did you see instead?
```
panic: internal error: can't find reason for requirement on golang.org/x/sync@v0.0.0-20220601150217-0de741cfad7f
goroutine 1 [running]:
cmd/go/internal/modget.(*resolver).updateBuildList.func1({{0xc0000281e0, 0x11}, {0xc000032690, 0x22}})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:1760 +0xd4
cmd/go/internal/modget.(*resolver).updateBuildList(0xc00023c000, {0xb2d5d0, 0xc00002c0f8}, {0x0, 0x0, 0x0})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:1765 +0x54c
cmd/go/internal/modget.(*resolver).resolveQueries(0xc00023c000, {0xb2d5d0, 0xc00002c0f8}, {0xc000014058, 0x1, 0xc0000a3d78?})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:1243 +0x1a5
cmd/go/internal/modget.runGet({0xb2d5d0, 0xc00002c0f8}, 0xc0000285e8?, {0xc0000240f0, 0x1, 0x1})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:314 +0x408
main.invoke(0xe371a0, {0xc0000240d0, 0x3, 0x3})
/home/icio/sdk/gotip/src/cmd/go/main.go:225 +0x3d9
main.main()
/home/icio/sdk/gotip/src/cmd/go/main.go:179 +0x7ce
```
### To reproduce
```
$ git clone https://github.com/icio/go-get-panic
Cloning into 'go-get-panic'...
remote: Enumerating objects: 7, done.
remote: Counting objects: 100% (7/7), done.
remote: Compressing objects: 100% (5/5), done.
remote: Total 7 (delta 1), reused 7 (delta 1), pack-reused 0
Receiving objects: 100% (7/7), done.
Resolving deltas: 100% (1/1), done.
$ cd go-get-panic
$ git checkout 2cbc2db2a48105fa2b71ec69d11b6496ba52c263
$ git rev-parse HEAD
2cbc2db2a48105fa2b71ec69d11b6496ba52c263
$ gotip version
go version devel go1.20-e09bbae Sat Oct 29 04:48:07 2022 +0000 linux/amd64
$ gotip get -u golang.org/x/tools
panic: internal error: can't find reason for requirement on golang.org/x/sync@v0.0.0-20220601150217-0de741cfad7f
goroutine 1 [running]:
cmd/go/internal/modget.(*resolver).updateBuildList.func1({{0xc0000281e0, 0x11}, {0xc000032690, 0x22}})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:1760 +0xd4
cmd/go/internal/modget.(*resolver).updateBuildList(0xc00023c000, {0xb2d5d0, 0xc00002c0f8}, {0x0, 0x0, 0x0})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:1765 +0x54c
cmd/go/internal/modget.(*resolver).resolveQueries(0xc00023c000, {0xb2d5d0, 0xc00002c0f8}, {0xc000014058, 0x1, 0xc0000a3d78?})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:1243 +0x1a5
cmd/go/internal/modget.runGet({0xb2d5d0, 0xc00002c0f8}, 0xc0000285e8?, {0xc0000240f0, 0x1, 0x1})
/home/icio/sdk/gotip/src/cmd/go/internal/modget/get.go:314 +0x408
main.invoke(0xe371a0, {0xc0000240d0, 0x3, 0x3})
/home/icio/sdk/gotip/src/cmd/go/main.go:225 +0x3d9
main.main()
/home/icio/sdk/gotip/src/cmd/go/main.go:179 +0x7ce
```
This reproduces even if you remove the go.sum:
```
$ rm go.sum && gotip get -u golang.org/x/tools 2>&1 | head -1
panic: internal error: can't find reason for requirement on golang.org/x/sync@v0.0.0-20220601150217-0de741cfad7f
```
Uncommenting any of the requirements in go.mod and re-running `go get -u golang.org/x/tools` will allow `go get` to succeed. E.g.:
```
$ sed -i '/x\/net/d' go.mod
$ git diff
diff --git a/go.mod b/go.mod
index cc0392c..05b38b1 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,6 @@ module github.com/icio/go-get-panic
go 1.18
require (
- golang.org/x/net v0.1.0
golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f
golang.org/x/text v0.4.0
)
$ go get -u golang.org/x/tools
go: downgraded golang.org/x/text v0.4.0 => v0.3.7
go: upgraded golang.org/x/tools v0.1.12 => v0.2.0
```
In the repository where I first encountered, this I was able to fix `go get -u golang.org/x/tools` by removing the `golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f` line. Next, re-running `go mod tidy` reintroduces `golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f` to go.mod. I'm not sure if this is related, but despite having a ./go.mod at the root of the project, we also have a ./cmd/ci-test-utility/go.mod which contains `golang.org/x/sync v0.0.0-20220601150217-0de741cfad7f`.
Typically if plugins upgrade to use the latest Caddy version (now 2.6.4, and this topic is for 2.6.3) it seems to fix the problem. We don’t know why.