Copy asco-test.exe and ngspice_c.exe (console executable of ngspice) into the directory, and run

$ asco-test -ngspice amp3

from the console window. Several files will be created during checking. If you look at <computer-name>.sp: this is the input file for ngspice_c, generated by ASCO. You will find the additional .measure commands and .control sections. The quit command will be added automatically just before the .endc command in its own .control section. asco-test will display error messages on the console, if the simulation or communication with ASCO is not ok. The output file <computer-name>.out, generated by ngspice during each simulation, contains symbols like zac_power0, zdc_gain1, zunity_gain_frequency2, zphase_margin3, zphase_margin4, and zamp3_slew_rate5. These are used to communicate the ngspice output data to ASCO. ASCO is searching for something like zdc_gain1 =, and then takes the next token as the input value. Calling phase_margin twice in amp3.cfg has lead to two measurements in two .control sections with different symbols (zphase_margin3, zphase_margin4).

A failing test may result in an error message from ASCO. Sometimes, however, ASCO freezes after some output statements. This may happen if ngspice issues an error message that cannot be handled by ASCO. Here it may help calling ngspice directly with the input file generated by ASCO:

$ ngspice_c <computer-name>.sp

Thus you may evaluate the ngspice messages directly.