text/template: bad format string for range-over-int error

[jba]

Go version

go version devel go1.24-5fe3b31cf8 Fri Sep 27 16:45:09 2024 +0000 linux/amd64

Output of go env in your module/workspace:

GO111MODULE='on'                                                                                                               
GOARCH='amd64'
GOBIN=''
GOCACHE='/usr/local/google/home/jba/.cache/go-build'                                                                           
GOENV='/usr/local/google/home/jba/.config/go/env'
GOEXE=''
GOEXPERIMENT='fieldtrack,boringcrypto'
GOFLAGS=''
GOHOSTARCH='amd64'                                                                                                             
GOHOSTOS='linux'
GOINSECURE=''
GOMODCACHE='/usr/local/google/home/jba/go/pkg/mod'                                                                             
GONOPROXY=''
GONOSUMDB=''                                                                                                                   
GOOS='linux'                                                                                                                   
GOPATH='/usr/local/google/home/jba/go'                                                                                         
GOPRIVATE=''
GOPROXY='https://proxy.golang.org'
GOROOT='/usr/lib/google-golang'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/usr/lib/google-golang/pkg/tool/linux_amd64'
GOVCS=''
GOVERSION='go1.23-20240626-RC01 cl/646990413 +5a18e79687 X:fieldtrack,boringcrypto'                                            
GODEBUG=''
GOTELEMETRY='on'                                                                                                               
GOTELEMETRYDIR='/usr/local/google/home/jba/.config/go/telemetry'                                                               
GCCGO='gccgo'
GOAMD64='v1'
AR='ar'
CC='clang'                                                                                                                     
CXX='clang++'                                                                                                                  
CGO_ENABLED='1'
GOMOD='/usr/local/google/home/jba/repos/github.com/jba/templatecheck/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 -fno-caret-diagnostics -Qunused-arguments -Wl,--no-gc-sections -fmessage-length=0 -ffile-prefix-map=/tmp/go-build2774739339=/tmp/go-build -gno-record-gcc-switches'

What did you do?

template.Must(ttmpl.New("").Parse(`{{range $x, $y := .}}{{.}}{{end}}`))

where template is text/template

What did you see happen?

template: :1:18: executing "" at <.>: can't use %!s(int=5) to iterate over more than one variable

(emphasis mine)

What did you expect to see?

maybe

template: :1:18: executing "" at <.>: can't use int=5 to iterate over more than one variable

[gabyhelp]

Related Issues and Documentation

• error with range can't traverse "\xd5\xbc\xbd\xbe" #25306 (closed)
• text/template: Unexpected assignment #56490 (closed)
• text/template: key/value assignment is reversed within range loop #60801 (closed)
• cmd/compile: range over rune literal causes internal compiler error #64471 (closed)
• cmd/go: build tags do not work quite as expected using devel version of Go #66299 (closed)
• x/tools/gopls: range over func without variable shows 'simplify range expression' warning #65799 (closed)
• cmd/compile: out of range integer in range loop crashes the compiler #65133 (closed)
• html/template: {{range}} branches end in different contexts #54999 (closed)
• x/tools/gopls: issues errors for range-over-func (InvalidRangeExpr) in go1.23rc1 projects #68248 (closed)
• A text template rendering fine on 1.13 causes an error on 1.14rc1 #37066 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[jba]

Related to #66107.

[gopherbot]

Change https://go.dev/cl/616695 mentions this issue: text/template: use correct verbs for reflect.Value