Here's the output:

GL Context creation suceeded.
Mesa: User error: GL_INVALID_OPERATION in glUseProgram(program 3 not linked)
^C0:1(1): error: syntax error, unexpected $end0:1(1): error: syntax error,
unexpected $endGL_INVALID_OPERATION in glUseProgram(program 3 not linked)Shader
Stats: SGPRS: 24 VGPRS: 16 Code Size: 64 LDS: 0 Scratch: 0 Max Waves: 10
Spilled SGPRs: 0 Spilled VGPRs: 0Shader Stats: SGPRS: 16 VGPRS: 16 Code Size:
40 LDS: 0 Scratch: 0 Max Waves: 10 Spilled SGPRs: 0 Spilled VGPRs: 0Shader
Stats: SGPRS: 18 VGPRS: 8 Code Size: 252 LDS: 0 Scratch: 0 Max Waves: 10
Spilled SGPRs: 0 Spilled VGPRs: 0Shader Stats: SGPRS: 16 VGPRS: 16 Code Size:
64 LDS: 0 Scratch: 0 Max Waves: 10 Spilled SGPRs: 0 Spilled VGPRs: 0Shader
Stats: SGPRS: 16 VGPRS: 16 Code Size: 40 LDS: 0 Scratch: 0 Max Waves: 10
Spilled SGPRs: 0 Spilled VGPRs: 0

Again, this is with a debug build of Mesa, but there should be no difference in
error checking -- only the output when an error is detected is different.