Docker build problem: undefined: io.ReadAll

[suntong]

Docker build problem unrelated with #425.

Building with the Dockerfile and I'm getting undefined: io.ReadAll:

Making install in test
. . .
Making install in helpers
. . .
Making install in fuzz
. . .
 /bin/mkdir -p '/vips/lib/pkgconfig'
 /usr/bin/install -c -m 644 vips.pc vips-cpp.pc '/vips/lib/pkgconfig'
make[2]: Leaving directory '/tmp/vips-8.9.2'
make[1]: Leaving directory '/tmp/vips-8.9.2'
Removing intermediate container bca6677ddce0
 ---> 5f9c29cec351
Step 7/11 : ENV LD_LIBRARY_PATH="/usr/local/lib:$LD_LIBRARY_PATH"
 ---> Running in dc1baddc6296
Removing intermediate container dc1baddc6296
 ---> f3d093987363
Step 8/11 : RUN go get -u golang.org/x/lint/golint
 ---> Running in ee17eb370211
# golang.org/x/tools/internal/gcimporter
src/golang.org/x/tools/internal/gcimporter/gcimporter.go:223:15: undefined: io.ReadAll
The command '/bin/sh -c go get -u golang.org/x/lint/golint' returned a non-zero code: 2