Lots of questions: what device? What board or dev kit? Have you programmed the device with a design that includes a Nios II? Does device programming work at all using a .sof file and the Quartus Programmer?
--- Quote Start --- Lots of questions: what device? What board or dev kit? Have you programmed the device with a design that includes a Nios II? Does device programming work at all using a .sof file and the Quartus Programmer? --- Quote End --- The device is a Max10 10M50DAF484C6GES. The board is the MAX10 FPGA Development Kit. The fabric has been programmed with a design that includes the Nios II. I can flash the design from inside Quartus (by double clicking on Program Device, which opens up the Programmer), or by programming it from inside the Nios II Eclipse environment (by clicking Nios II->Quartus Prime Programmer and loading the .cdf, .sof, or .pof). I can program with both a .sof and a .pof. Here's what I've tries to do: when I run->debug configurations->Target Connection, I see a message "The expected Stdout device name does not match the selected target byte stream device name." If I click on "Debug" anyway, I get a "Downloading ELF Process failed" message. If I "Refresh Connections," sometimes it works, and sometimes it crashes Eclipse. If, after I "Refresh Connections," I "Resolve Names," nothing much appears to happen. If I then click on "System ID Properties," I get a menu full of information: "Expected system ID base address: 0xc10e0, Expected system ID: 0, Connected system ID: Not found, Expected system timestamp: 1500423637, Connected system timestamp: Not Found." Sometimes clicking "Refresh Connections" returns "No Nios II target connection paths were located," but if I click it again, sometimes it comes back with the "The expected Stdout device name does not match" message...and sometimes it just hangs Eclipse.
One other data point. I was told to slow the jtag clock down by typing "jtagconfig --setparam 1 JayClock 6M" in the Altera Nios2 Command Shell. There seems to be some correlation between doing this and the hangs.