Attempting to deploy a .net 8.0 website

I am getting this error:
✕ [6/9] RUN dotnet restore

process "/bin/bash -ol pipefail -c dotnet restore" did not complete successfully: exit code: 1
I also see this warning, even though there is only one .csproj in the solution in visual studio:
MSBUILD : error MSB1011: Specify which project or solution file to use because this folder contains more than one project or solution file.|

The following is the whole build log:
deleting '/nix/store/wgqxfhs0zj7fl182nk92rsslp796cjx4-ed-1.19'

deleting '/nix/store/7nfcdvrmdbpms7wcrjjsqwkv07lswhli-gzip-1.13'

deleting '/nix/store/s806iqg5vwsnp434i5whcn1rf605y9s6-gnumake-4.4.1'

deleting '/nix/store/kfrcs055nxbkwd6yy39h5xxyrj8wrb73-xz-5.4.4'

deleting '/nix/store/yqa5m326a0ynn4whm4fikyjfljfc6i3q-gmp-with-cxx-6.3.0'

deleting '/nix/store/v553h3r3f0xqxpvb9pgzx006qrmmv12m-patchelf-0.15.0'

deleting '/nix/store/jx3kvf6mk8qdaw30dbpngwmgm4p23xdb-libxcrypt-4.4.36'

deleting '/nix/store/dc4lnyzdwfck9fc9h8h6n7di5yki5ilx-builder.pl'

deleting unused links...

note: currently hard linking saves 38.30 MiB

32 store paths deleted, 211.60 MiB freed

[4/9] RUN nix-env -if .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix && nix-collect-garbage -d 40s

[5/9] COPY . /app/.

[5/9] COPY . /app/. 128ms

[6/9] RUN dotnet restore

Welcome to .NET 8.0! --------------------- SDK Version: 8.0.100-preview.5.23303.2 Telemetry --------- The .NET tools collect usage data in order to help us improve your experience. It is collected by Microsoft and shared with the community. You can opt-out of telemetry by setting the DOTNET_CLI_TELEMETRY_OPTOUT environment variable to '1' or 'true' using your favorite shell. Read more about .NET CLI Tools telemetry: https://aka.ms/dotnet-cli-telemetry

---------------- Installed an ASP.NET Core HTTPS development certificate. To trust the certificate run 'dotnet dev-certs https --trust' (Windows and macOS only). Learn about HTTPS: https://aka.ms/dotnet-https ---------------- Write your first app: https://aka.ms/dotnet-hello-world Find out what's new: https://aka.ms/dotnet-whats-new Explore documentation: https://aka.ms/dotnet-docs Report issues and find source on GitHub: https://github.com/dotnet/core Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli --------------------------------------------------------------------------------------

MSBUILD : error MSB1011: Specify which project or solution file to use because this folder contains more than one project or solution file.

✕ [6/9] RUN dotnet restore

process "/bin/bash -ol pipefail -c dotnet restore" did not complete successfully: exit code: 1

Dockerfile:19

-------------------

17 | # install phase

18 | COPY . /app/.

19 | >>> RUN dotnet restore

20 |

21 | # build phase

-------------------

ERROR: failed to build: failed to solve: process "/bin/bash -ol pipefail -c dotnet restore" did not complete successfully: exit code: 1

Error: Docker build failed