Set ErrorActionPreference on all powershell scripts and add explicit error checks.

.circleci/build_win.ps1

@@ -1,3 +1,5 @@
+$ErrorActionPreference = "Stop"
+
 cd "$PSScriptRoot\.."
 
 if ("$Env:FORCE_RELEASE") {
@@ -9,5 +11,8 @@ mkdir build
 cd build
 $boost_dir=(Resolve-Path $PSScriptRoot\..\deps\boost\lib\cmake\Boost-*)
 ..\deps\cmake\bin\cmake -G "Visual Studio 16 2019" -DBoost_DIR="$boost_dir\" -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded -DCMAKE_INSTALL_PREFIX="$PSScriptRoot\..\upload" ..
+if ( -not $? ) { throw "CMake configure failed." }
 msbuild solidity.sln /p:Configuration=Release /m:5 /v:minimal
+if ( -not $? ) { throw "Build failed." }
 ..\deps\cmake\bin\cmake --build . -j 5 --target install --config Release
+if ( -not $? ) { throw "Install target failed." }

.circleci/soltest.ps1

@@ -1,7 +1,12 @@
+$ErrorActionPreference = "Stop"
+
 cd "$PSScriptRoot\.."
 
 .\build\solc\Release\solc.exe --version
+if ( -not $? ) { throw "Cannot execute solc --version." }
 
 mkdir test_results
 .\build\test\Release\soltest.exe --color_output=no --show_progress=yes --logger=JUNIT,error,test_results/result.xml -- --no-smt
+if ( -not $? ) { throw "Unoptimized soltest run failed." }
 .\build\test\Release\soltest.exe --color_output=no --show_progress=yes --logger=JUNIT,error,test_results/result_opt.xml -- --optimize --no-smt
+if ( -not $? ) { throw "Optimized soltest run failed." }

scripts/install_deps.ps1

@@ -1,3 +1,5 @@
+$ErrorActionPreference = "Stop"
+
 # Needed for Invoke-WebRequest to work via CI.
 $progressPreference = "silentlyContinue"
 
@@ -12,4 +14,5 @@ tar -xf boost.zip
 cd boost_1_74_0
 .\bootstrap.bat
 .\b2 -j4 -d0 link=static runtime-link=static variant=release threading=multi address-model=64 --with-filesystem --with-system --with-program_options --with-test --prefix="$PSScriptRoot\..\deps\boost" install
+if ( -not $? ) { throw "Error building boost." }
 cd ..

scripts/install_evmone.ps1

@@ -1,3 +1,5 @@
+$ErrorActionPreference = "Stop"
+
 # Needed for Invoke-WebRequest to work via CI.
 $progressPreference = "silentlyContinue"