Docker run is unable to locate the directory – Ubuntu

I’ve built a docker image, docker build -t dockeragent:latest . but can’t seem to trigger the container to run. The command: docker run -e AZP_URL=<obfuscate> -e AZP_TOKEN=<obfuscate> -e AZP_AGENT_NAME=mydockeragent dockeragent:latest produces the following error: exec ./start.sh: no such file or directory.

I understand that the start.sh script is called by the Dockerfile and I’ve ensured that the Dockerfile is in the same directory as the start.sh script. I’ve also tested referencing the start.sh script by using interpolation to point to the absolute path pointing to the start.sh script. Example:
ENTRYPOINT [ "${pwd}/start.sh" ]

Any ideas on what parameter has been misconfigured? The files are directly copied from Micorosft’s guide on building self-hosted agents with Docker

For reference, please see the below Dockerfile and associated start.sh

Dockerfile

FROM ubuntu:20.04
RUN DEBIAN_FRONTEND=noninteractive apt-get update
RUN DEBIAN_FRONTEND=noninteractive apt-get upgrade -y

RUN DEBIAN_FRONTEND=noninteractive apt-get install -y -qq --no-install-recommends 
    apt-transport-https 
    apt-utils 
    ca-certificates 
    curl 
    git 
    iputils-ping 
    jq 
    lsb-release 
    software-properties-common

RUN curl -sL https://aka.ms/InstallAzureCLIDeb | bash

# Can be 'linux-x64', 'linux-arm64', 'linux-arm', 'rhel.6-x64'.
ENV TARGETARCH=linux-x64

WORKDIR /azp

COPY ./start.sh .
RUN chmod +x start.sh

ENTRYPOINT [ "./start.sh" ]

start.sh

#!/bin/bash
set -e

if [ -z "$AZP_URL" ]; then
  echo 1>&2 "error: missing AZP_URL environment variable"
  exit 1
fi

if [ -z "$AZP_TOKEN_FILE" ]; then
  if [ -z "$AZP_TOKEN" ]; then
    echo 1>&2 "error: missing AZP_TOKEN environment variable"
    exit 1
  fi

  AZP_TOKEN_FILE=/azp/.token
  echo -n $AZP_TOKEN > "$AZP_TOKEN_FILE"
fi

unset AZP_TOKEN

if [ -n "$AZP_WORK" ]; then
  mkdir -p "$AZP_WORK"
fi

export AGENT_ALLOW_RUNASROOT="1"

cleanup() {
  if [ -e config.sh ]; then
    print_header "Cleanup. Removing Azure Pipelines agent..."

    # If the agent has some running jobs, the configuration removal process will fail.
    # So, give it some time to finish the job.
    while true; do
      ./config.sh remove --unattended --auth PAT --token $(cat "$AZP_TOKEN_FILE") && break

      echo "Retrying in 30 seconds..."
      sleep 30
    done
  fi
}

print_header() {
  lightcyan='33[1;36m'
  nocolor='33[0m'
  echo -e "${lightcyan}$1${nocolor}"
}

# Let the agent ignore the token env variables
export VSO_AGENT_IGNORE=AZP_TOKEN,AZP_TOKEN_FILE

print_header "1. Determining matching Azure Pipelines agent..."

AZP_AGENT_PACKAGES=$(curl -LsS 
    -u user:$(cat "$AZP_TOKEN_FILE") 
    -H 'Accept:application/json;' 
    "$AZP_URL/_apis/distributedtask/packages/agent?platform=$TARGETARCH&top=1")

AZP_AGENT_PACKAGE_LATEST_URL=$(echo "$AZP_AGENT_PACKAGES" | jq -r '.value[0].downloadUrl')

if [ -z "$AZP_AGENT_PACKAGE_LATEST_URL" -o "$AZP_AGENT_PACKAGE_LATEST_URL" == "null" ]; then
  echo 1>&2 "error: could not determine a matching Azure Pipelines agent"
  echo 1>&2 "check that account '$AZP_URL' is correct and the token is valid for that account"
  exit 1
fi

print_header "2. Downloading and extracting Azure Pipelines agent..."

curl -LsS $AZP_AGENT_PACKAGE_LATEST_URL | tar -xz & wait $!

source ./env.sh

print_header "3. Configuring Azure Pipelines agent..."

./config.sh --unattended 
  --agent "${AZP_AGENT_NAME:-$(hostname)}" 
  --url "$AZP_URL" 
  --auth PAT 
  --token $(cat "$AZP_TOKEN_FILE") 
  --pool "${AZP_POOL:-Default}" 
  --work "${AZP_WORK:-_work}" 
  --replace 
  --acceptTeeEula & wait $!

print_header "4. Running Azure Pipelines agent..."

trap 'cleanup; exit 0' EXIT
trap 'cleanup; exit 130' INT
trap 'cleanup; exit 143' TERM

chmod +x ./run-docker.sh

# To be aware of TERM and INT signals call run.sh
# Running it with the --once flag at the end will shut down the agent after the build is executed
./run-docker.sh "$@" & wait $!

Thanks in advance!