HTTP binary cache fails with Value was null

[jpires]

Hello all,

I am having an issue with the HTTP binary caching, that it fails to check the packages on the server.
The message that I am getting is internal error: /vcpkg/buildtrees/_vcpkg/src/vcpkg-tool-2025-01-11/src/vcpkg/base/downloads.cpp(925): Value was null

There's a link between the number of packages that it needs to check and after around 25 checks, it fails.
Also this is a regression as this works without any issues on the 2024.12.16 Release

I did some basic debugging and it seems that in the older versions, vcpkg noticed that curl had given a partial response and would try again in a few milliseconds.

Restored 0 package(s) from /root/.cache/vcpkg/archives in 106 us. Use --debug to see more details.
warning: curl returned a partial response; waiting 100 milliseconds and trying again
Restored 0 package(s) from HTTP servers in 147 ms. Use --debug to see more details.

But with the newest version that message doesn't exist and it seems that vcpkg is trying to parse the progress report from curl.
I have added a print on parse_curl_status_line to print the this_line.
And it fails with the following this_line
Curl status line: 5ec47b8e-6776-4d70-b9b3-ac2a57bc0a1c % Total % Received % Xferd Average Speed Time Time Time Current

Let me know if you need more details.

BTW, this doesn't seem to be an issue on macOS.

How to reproduce.

I have run this tests inside docker using alpine 3.21
These steps use a local HTTP server, but it doesn't matter, as the initial failure was detected with an artefact repository.
Where some of the dependencies exist and other don't.

Create the following project
vcpkg.json

{
  "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg.schema.json",
  "builtin-baseline": "7eb700c9688daed6d8bdcdc571ebe3eedea6a774",
  "dependencies": [
    {
      "name": "asio",
      "version>=": "1.30.2"
    },
    {
      "name": "boost-preprocessor",
      "version>=": "1.85.0"
    },
    {
      "name": "boost-uuid",
      "version>=": "1.85.0"
    },
    {
      "name": "catch2",
      "version>=": "3.6.0"
    },
    {
      "name": "date",
      "version>=": "3.0.1#5"
    },
    {
      "name": "fakeit",
      "version>=": "2.4.0#2"
    },
    {
      "name": "libconfig",
      "version>=": "1.7.3#5"
    },
    {
      "name": "libmodbus",
      "version>=": "3.1.10"
    },
    {
      "name": "mpark-variant",
      "version>=": "1.4.0#3"
    },
    {
      "name": "openssl",
      "version>=": "3.3.0#1"
    },
    {
      "name": "protobuf",
      "version>=": "3.21.12#2"
    },
    {
      "name": "spdlog",
      "version>=": "1.14.1"
    },
    {
      "name": "sqlite3",
      "version>=": "3.45.3#1",
      "features": ["dbstat", "limit"]
    },
    {
      "name": "tl-expected",
      "version>=": "1.1.0"
    },
    {
      "name": "websocketpp",
      "version>=": "0.8.2#3",
      "default-features": false
    }
  ],
  "name": "agent",
  "version": "1.0.0"
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.14)

project(hello-world)

CMakePresets.json

{
  "version": 2,
  "cmakeMinimumRequired": {
    "major": 3,
    "minor": 14,
    "patch": 0
  },
  "configurePresets": [
    {
      "name": "dev",
      "binaryDir": "${sourceDir}/build/dev",
      "cacheVariables": {
        "CMAKE_TOOLCHAIN_FILE": "/vcpkg/scripts/buildsystems/vcpkg.cmake"
      },
      "environment": {
        "VCPKG_BINARY_SOURCES": "http,http://localhost:8080/vcpkg/{name}/{triplet}/{version}-{sha},readwrite,Authorization: Basic $env{CLOUDREPO_AUTH}"
      },
      "generator": "Ninja"
    }
  ],
  "buildPresets": [
    {
      "name": "build-amd64",
      "configurePreset": "dev",
      "targets": [
        "hello_c",
        "hello_cpp",
        "hello_fmt"
      ]
    }
  ]
}

Launch a simple HTTP server, so that curl doesn't fail immediately.
I used python with python3 -m http.server 8080

Then try to configure the project with cmake --presets dev