Unable to build on Ubuntu

[rcjsuen]

$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.2 LTS
Release:	18.04
Codename:	bionic

$ msbuild /version
Microsoft (R) Build Engine version 16.0.0.0 for Mono
Copyright (C) Microsoft Corporation. All rights reserved.

16.0.0.0

$ mono --version
Mono JIT compiler version 5.20.1.19 (tarball Thu Apr 11 09:02:17 UTC 2019)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           __thread
	SIGSEGV:       altstack
	Notifications: epoll
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	Interpreter:   yes
	LLVM:          yes(600)
	Suspend:       hybrid
	GC:            sgen (concurrent by default)

$ ./build.sh 
Feeds used:
  /home/remy/.nuget/packages/
  https://api.nuget.org/v3/index.json
  https://dotnet.myget.org/F/dotnet-core/api/v3/index.json
  https://dotnet.myget.org/F/dotnet-cli/api/v3/index.json
  https://www.myget.org/F/omnisharp/api/v3/index.json
  https://dotnet.myget.org/F/roslyn/api/v3/index.json

All packages listed in /home/remy/code/github/omnisharp-roslyn/tools/packages.config are already installed.
/proc/self/maps:
40085000-400d5000 rwxp 00000000 00:00 0 
40fe2000-40ff2000 rwxp 00000000 00:00 0 
55ab8f9d0000-55ab8fe21000 r-xp 00000000 103:05 794355                    /usr/bin/mono-sgen
55ab90021000-55ab90028000 r--p 00451000 103:05 794355                    /usr/bin/mono-sgen
55ab90028000-55ab9002d000 rw-p 00458000 103:05 794355                    /usr/bin/mono-sgen
55ab9002d000-55ab90044000 rw-p 00000000 00:00 0 
55ab914ee000-55ab917fd000 rw-p 00000000 00:00 0                          [heap]
7fc140000000-7fc140021000 rw-p 00000000 00:00 0 
7fc140021000-7fc144000000 ---p 00000000 00:00 0 
7fc144000000-7fc144021000 rw-p 00000000 00:00 0 
7fc144021000-7fc148000000 ---p 00000000 00:00 0 
7fc148000000-7fc14802a000 rw-p 00000000 00:00 0 
7fc14802a000-7fc14c000000 ---p 00000000 00:00 0 
7fc14c000000-7fc14c037000 rw-p 00000000 00:00 0 
7fc14c037000-7fc150000000 ---p 00000000 00:00 0 
7fc150000000-7fc150021000 rw-p 00000000 00:00 0 
7fc150021000-7fc154000000 ---p 00000000 00:00 0 
7fc155f8b000-7fc1561d8000 r-xp 00000000 103:05 786554                    /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7fc1561d8000-7fc1563d8000 ---p 0024d000 103:05 786554                    /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7fc1563d8000-7fc156400000 rw-p 0024d000 103:05 786554                    /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1
7fc156400000-7fc156403000 rw-p 00000000 00:00 0 
7fc156403000-7fc156463000 r-xp 00000000 103:05 787226                    /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7fc156463000-7fc156663000 ---p 00060000 103:05 787226                    /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7fc156663000-7fc15666d000 rw-p 00060000 103:05 787226                    /usr/lib/x86_64-linux-gnu/libssl.so.1.1
7fc1570fb000-7fc1570fc000 ---p 00000000 00:00 0 
Error: One or more errors occurred. (Expecting state 'Element'.. Encountered 'Text'  with name '', namespace ''.)
	Expecting state 'Element'.. Encountered 'Text'  with name '', namespace ''.

[alecvn]

I'm on exactly the same OS and other software versions as you and can confirm I ran into this identical issue.

[jamievlin]

Not only that, but I also get an identical error on Arch Linux with

Mono JIT compiler version 5.20.1 (makepkg/886c4901747 Wed Apr 17 15:49:14 UTC 2019)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
	TLS:           __thread
	SIGSEGV:       altstack
	Notifications: epoll
	Architecture:  amd64
	Disabled:      none
	Misc:          softdebug 
	Interpreter:   yes
	LLVM:          supported, not enabled.
	Suspend:       hybrid
	GC:            sgen (concurrent by default)

and the same msbuild as @rcjsuen.

[nickenchev]

Same thing on Arch.
Linux office-arch 5.2.1-arch1-1-ARCH #1 SMP PREEMPT Sun Jul 14 14:52:52 UTC 2019 x86_64 GNU/Linux

[vitalybaev]

Same

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.2 LTS
Release:        18.04
Codename:       bionic

$ msbuild /version
Microsoft (R) Build Engine version 16.0.0.0 for Mono
Copyright (C) Microsoft Corporation. All rights reserved.

16.0.0.0

$ mono --version
Mono JIT compiler version 6.0.0.319 (tarball Mon Aug 12 23:46:26 UTC 2019)
Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors. www.mono-project.com
        TLS:           __thread
        SIGSEGV:       altstack
        Notifications: epoll
        Architecture:  amd64
        Disabled:      none
        Misc:          softdebug 
        Interpreter:   yes
        LLVM:          yes(600)
        Suspend:       hybrid
        GC:            sgen (concurrent by default)