Using builder to build custom receiver in Docker is really slow

[mmynk]

My Dockerfile looks something like below:

# Setup the OpenTelemetry Collector and its dependencies
FROM golang:1-bookworm AS oteld-build

# mdatagen cannot be installed via go install, see: https://github.com/open-telemetry/opentelemetry-collector/issues/9281
# RUN go install github.com/open-telemetry/opentelemetry-collector/cmd/mdatagen@latest
ARG OTELCOL_VERSION=v0.118.0
RUN git clone --branch ${OTELCOL_VERSION} --depth 1 https://github.com/open-telemetry/opentelemetry-collector.git && \
    cd opentelemetry-collector/cmd/mdatagen && \
    go install .

# Install dependencies
RUN go install go.opentelemetry.io/collector/cmd/builder@${OTELCOL_VERSION} && \
    // other dependencies

WORKDIR /otel

# Copy the source code
COPY src ./

# Download go modules
RUN go mod download

# Generate metadata
RUN cd exporters/customreceiver && go mod download && go generate
RUN cd /otel/exporters/customreceiver && mdatagen metadata.yaml

# Build the OpenTelemetry Collector
RUN builder --config builder-config.yaml

# Build the final image
FROM debian:bookworm-slim AS oteld-final

COPY --chmod=755 --from=otel-build /otel/otelcol-dev/otel /otel
# /config.yaml should be mounted by the user
ENTRYPOINT ["/otel", "--config", "/config.yaml"]

Even though I expect go mod download to download most dependencies, the RUN builder ... step is excruciatingly slow with even a small change to the custom receiver.

It gets stuck at Compiling... sometimes around 5 mins or so. Iterative building using Docker makes this a bad experience.

Anything I could do to improve the build time? Maybe mount the go module path? Would appreciate suggestions.