`dotnet pack` throws error

Description

getting this error:

$ dotnet pack src/CryptoExchangeClient.fsproj --include-symbols --include-source

/home/me/Development/NullVoxPopuli/CryptoExchangeClient/.paket/Paket.Restore.targets(190,5): error : Could not find a part of the path '/home/me/Development/NullVoxPopuli/CryptoExchangeClient/src/obj/Debug/CryptoExchangeClient.0.4.0.nuspec;/home/me/Development/NullVoxPopuli/CryptoExchangeClient/src/obj/Debug'. [/home/me/Development/NullVoxPopuli/CryptoExchangeClient/src/CryptoExchangeClient.fsproj]

but,

ls -la /home/me/Development/NullVoxPopuli/CryptoExchangeClient/src/obj/Debug/

total 28K
drwxrwxr-x 3 me me 4.0K Apr 18 08:45 .
drwxrwxr-x 3 me me 4.0K Apr 18 08:45 ..
-rw-rw-rw- 1 me me 1.9K Apr 18 09:13 CryptoExchangeClient.0.4.0.nuspec
-rw-rw-rw- 1 me me 8.6K Apr 18 09:13 CryptoExchangeClient.0.4.0.symbols.nuspec
drwxrwxr-x 2 me me 4.0K Apr 18 08:45 netcoreapp2.0

Please provide a succinct description of your issue.

Repro steps

clone https://github.com/NullVoxPopuli/CryptoExchangeClient
commit at time of creating this issue: 7c02e6d15f9a2400eacdc736ad4c21c47aa0bcb9

run:

./run release:clean

(alias for clean, build, release, should fail on the dotnet pack step)

Expected behavior

nuget package to be packed

Actual behavior

the error above

Known workarounds

none

verbose log

https://gist.github.com/NullVoxPopuli/6751fe49219be96978283b95319e258c

dotnet --info

$ dotnet --info
.NET Command Line Tools (2.1.104)

Product Information:
 Version:            2.1.104
 Commit SHA-1 hash:  48ec687460

Runtime Environment:
 OS Name:     ubuntu
 OS Version:  16.04
 OS Platform: Linux
 RID:         ubuntu.16.04-x64
 Base Path:   /usr/share/dotnet/sdk/2.1.104/

Host (useful for support):
  Version: 2.1.0-preview3-26412-03
  Commit:  2c6cdf715b

.NET Core SDKs installed:
  2.0.0 [/usr/share/dotnet/sdk]
  2.1.104 [/usr/share/dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.NETCore.App 2.0.0 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.0.6 [/usr/share/dotnet/shared/Microsoft.NETCore.App]
  Microsoft.NETCore.App 2.1.0-preview3-26412-03 [/usr/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

Reproduce the failure by cloning the repository at commit 7c02e6d15f9a2400eacdc736ad4c21c47aa0bcb9 and running ./run release:clean. Start with src/CryptoExchangeClient.fsproj and .paket/Paket.Restore.targets around line 190, using the linked verbose log for context. Done means the dotnet pack step completes and produces the expected NuGet package.