Build command incorrectly handles dependencies

[alexkaratarakis]

E:\workspace\vcpkg> vcpkg list
boost:x86-windows-static 1.62-2 Peer-reviewed portable C++ source libraries
cpprestsdk:x86-windows-static 2.9.0-1 C++11 JSON, REST, and OAuth library The C++ RES...
openssl:x86-windows-static 1.0.2j OpenSSL is an open source project that provides a...
zlib:x86-windows-static 1.2.8 A compression library

E:\workspace\vcpkg> vcpkg build cpprestsdk:x86-windows-static
The build command requires all dependencies to be already installed.
The following dependencies are missing:

zlib:x86-windows-static
boost:x86-windows-static
openssl:x86-windows-static

[GeertVL-zz]

Do they need to be installed automatically when you run the build command?

[alexkaratarakis]

The install command will handle dependencies automatically and you can specify multiple arguments.
The build command is internal/undocumented, so the current intention was to have all dependencies installed before you run build, and there is a verification for it. Also build only allows 1 package to be specified.

This is because, if (for example) you request for cpprestsdk which depends on zlib, boost, openssl, then install will result in:
zlib = installed
openssl= = installed
boost = installed
cpprestsdk = installed

and build would result in:
zlib = installed
openssl= = installed
boost = installed
cpprestsdk = built but not installed

This feels a bit unexpected. This is further complicated if you do something like:
vcpkg build cpprestsdk zlib
(Should zlib be installed or not?).

Regarding the current bug: Fixed with 2584f3e