Otherwise build compiles the packages but discards the results,
serving only as a check that the packages can be built.
-The -o flag specifies the output file name. If not specified, the
-name is packagename.a (for a non-main package) or the base
-name of the first source file (for a main package).
+The -o flag specifies the output file name. If not specified, the
+output file name depends on the arguments and derives from the name
+of the package, such as p.a for package p, unless p is 'main'. If
+the package is main and file names are provided, the file name
+derives from the first file name mentioned, such as f1 for 'go build
+f1.go f2.go'; with no files provided ('go build'), the output file
+name is the base name of the containing directory.
The build flags are shared by the build, install, run, and test commands:
force rebuilding of packages that are already up-to-date.
-n
print the commands but do not run them.
+ -o file
+ specify output file name; see description above.
-p n
the number of builds that can be run in parallel.
The default is the number of CPUs available.